Move Java Mail configuration to application

[poikilotherm]

As with JDBC #7418 and JMS #7423, we can move the mail configuration to the application. This further reduces the necessary bash glue to install Dataverse or use in containers. It eases reconfiguration, too.

Using Java EE 7 @MailSessionDefinition for this.

This should make things much easier in cases like #3061, #5986, #5723, #4969. #5707

Let's ping some people from the mail service code base: @pdurbin @qqmyers @landreev @sekmiller

[poikilotherm]

OK while this is fairly easy to do (add annotation to MailServiceBean), I stumbled over something.

The database setting :SystemEmail is used to set the "From" address of the message. It is even used to explicitly avoid blocking for mails. (Thx @qqmyers !)

MailServiceBean.sendSystemMail():

dataverse/src/main/java/edu/harvard/iq/dataverse/MailServiceBean.java

Line 131 in 3fcc239

msg.setFrom(systemAddress);

MailServiceBean.sendMail():

dataverse/src/main/java/edu/harvard/iq/dataverse/MailServiceBean.java

Lines 183 to 184 in 3fcc239

	//Always send from system address to avoid email being blocked
	InternetAddress fromAddress=getSystemAddress();

What I find very confusing: why should we do this? The "From" address is already configured for the JavaMail resource:

dataverse/scripts/installer/as-setup.sh

Lines 180 to 182 in 3fcc239

	./asadmin $ASADMIN_OPTS create-javamail-resource --mailhost "$SMTP_SERVER" --mailuser "dataversenotify" --fromaddress "do-not-reply@${HOST_ADDRESS}" --property mail.smtp.port="${SMTP_SERVER_PORT}" mail/notifyMailSession
	else
	./asadmin $ASADMIN_OPTS create-javamail-resource --mailhost "$SMTP_SERVER" --mailuser "dataversenotify" --fromaddress "do-not-reply@${HOST_ADDRESS}" mail/notifyMailSession

When a sysadmin configures a mail account from, lets say GMail, this might cause a situation where the authenticated user may not send a mail with a differing mail from :SystemEmail.

So while I add the annotation, I'd vote to ease the situation by:

1. Remove the DB setting
2. Make the annotation easily configurable via MicroProfile Config API
3. Rely on the Session to set the from mail for us (as configured).

After wrting all of this I found a prior issue on this: #4210 (thanks @donsizemore !) So we might as well choose to keep these two code changes separate. Whatever you like best.