feat: support switch-case replacements and definitions at root level

[TTtie]

Adds support for switch-case style replacement in message actions, inspired by pattern matching found in modern programming languages, for example (preliminary syntax, some details may be subject to change):

<message text="The outcome is {outcome}">
    <replacements>
        <!-- 
             value supports formulas and may be omitted 
             (in this case, the match attribute in <case>
             is disallowed)
        -->
        <switch id="outcome" value="variable">
            <!-- matches if the formula result is 0 -->
            <case match="0" result="Outcome 1"/>
            
            <!-- matches if the formula result is 1 AND only-team-1 allows -->
            <case match="1" filter="only-team-1" result="`aOutcome 2"/>
            
            <!-- matches if only-team-2 allows regardless of formula result -->
            <case filter="only-team-2" result="`bOutcome 3"/>
            
            <!--
                full syntax (matches if the formula result is between 2 and 5,
                and the inner filter allows)
            -->
            <case>
                <match>2..5</match>
                <filter>
                    <all id="not-moving">
                        <variable var="player.vel_x">0</variable>
                        <variable var="player.vel_y">..0</variable>
                        <variable var="player.vel_z">0</variable>
                    </all>
                </filter>
                <result>`cOutcome 4</result>
            </case>
            
            <!-- a fallback value if no cases match (defaults to an empty component) -->
            <fallback>`dA fallback outcome</fallback>
        </switch>
    </replacements>
</message>

Additionally, replacements can now be specified at the root level:

<map>
    <replacements>
        <!--
            scope is required for all replacements except <player />
            and it will be enforced if specified
        -->
        <decimal id="decimal" value="money" scope="player" format="0.00"/>
        <switch id="team" scope="team">
            <case filter="only-team-1" result="`aLime"/>
        </switch>
        
        <!-- 
            This will error as only-team-1 is team-scoped
            Not true as of commit 54666274 anymore. `only-team-1` will match as it abstains.
        -->
        <switch id="team2" scope="match">
            <case filter="only-team-1" result="`aLime"/>
        </switch>
    </replacements>
    <actions>
        <action id="action" scope="match">
            <switch-scope inner="player">
                <message text="The variable is {variable} and your team is {team}!">
                    <replacements>
                        <!--
                            the syntax for replacement references is
                            <replacement id="local-id">global-id</replacement>
                        -->
                        <replacement id="variable">decimal</replacement>
                        <replacement id="team">team</replacement>
                    </replacements>
                </message>
            </switch-scope>
        </action>
    </actions>
</map>

---

Launch checklist:

• Cannot use higher-scope filters in <case> than defined in <switch>
• Cannot specify higher-scope replacements than defined in <action>
• Cannot use lower-scope variables in <switch> value
• Validation???
  • Using a reference of lower scope replacement should not work in a higher-scope action
  • Declaring a lower scope replacement in a higher scope action should not work?

[calcastor]

Testing with changes from this repo, with the exception of Grand Dueling and Chromatic Conquest which differ too much upstream for me to rebase the changes right now, everything seems to work as intended.

[Pablete1234]

If you don't specify a value, and do specify a match, you could end up with a weird error message:

"Unused node 'match'" alongside an "At least a filter or a match..." which may leave you puzzled if you were a mapdev

maybe an option would be:

Suggested change

	var filter = parser.filter(innerEl, "filter").optional(() -> {
	if (valueRange == null)
	throw new InvalidXMLException(
	"At least a filter or a match attribute must be specified", innerEl);
	return StaticFilter.ALLOW;
	});
	var filterParse = parser.filter(innerEl, "filter");
	var filter = valueRange == null ? filterParse.required() : filterParse.orAllow();

which will just mark filter as required (without mentioning match at all) if you've not specified match.
not sure if it's really better or worse, maybe the err message should be different depending on if value is specified or not? i really don't know what's better

[TTtie]

If you don't specify a value, and do specify a match, you could end up with a weird error message:

"Unused node 'match'" alongside an "At least a filter or a match..." which may leave you puzzled if you were a mapdev

That will never happen. Parsing errors interrupt the whole map loading process, and unused node warnings are the very last step in that process. The error message probably needs a rewrite given that match="..." is ignored when there's no value though.