Replace internal sniffs with PHPCSExtra Universal equivalents

[dereuromark]

While reviewing PHPCSExtra's Universal sniffs, a few of our internal sniffs duplicate functionality that Universal already provides. Since PHPCSExtra is already in installed_paths, we can drop the internal implementations and reference the Universal sniffs directly in PhpCollective/ruleset.xml.

Direct replacements

Internal sniff	Universal replacement
PhpCollective.ControlStructures.DisallowAlternativeControlStructures (Sniffs/ControlStructures/DisallowAlternativeControlStructuresSniff.php)	Universal.ControlStructures.DisallowAlternativeSyntax
PhpCollective.WhiteSpace.CommaSpacing (Sniffs/WhiteSpace/CommaSpacingSniff.php)	Universal.WhiteSpace.CommaSpacing

Not direct replacements (keep internal)

• ElseIfDeclarationSniff — Universal's IfElseDeclaration checks brace/newline placement, not merging else if into elseif. PSR2 already handles that.
• ArrayBracketSpacingSniff, ConcatenationSpacingSniff, DisallowTrailingCommaInSingleLineSniff, DisallowShorthandNullableTypeHintSniff, DocBlock*, SingleQuoteSniff, ShortCastSniff, NotEqualSniff, ConditionalExpressionOrderSniff, DisallowCloakingCheckSniff, UseWithAliasingSniff, FunctionNamespaceSniff — no Universal counterpart.