Refactor scan mailbox form and add flag for post-processing

Mails are filtered once by using an imap search and then by some globs
to filter files and subjects. Imap can search by subject via a
string-contains, but not via globs or patterns (afaik). The subject
filter is applied to all downloaded mail headers. Now for post
processing (moving to some target folder or deleting), it can be
chosen to post-process all "seen" mails or only those that matched all
filters.

modules/common/src/main/scala/docspell/common/ScanMailboxArgs.scala

@@ -37,7 +37,9 @@ case class ScanMailboxArgs(
     // a glob filter for the mail subject
     subjectFilter: Option[Glob],
     // the language for extraction and analysis
-    language: Option[Language]
+    language: Option[Language],
+    // apply additional filter to all mails or only imported
+    postHandleAll: Option[Boolean]
 )
 
 object ScanMailboxArgs {