Issue #3591380: Add Mailer Plus 2.x compatibility

wlofgrenrequested to merge
issue/symfony_mailer_log-3591380:3591380-add-support-for into 1.2.x
  • Convert EmailAdjuster plugin annotation to attribute
  • Add transport DSN helper for 2.x compatibility
  • Parse type/subtype from tag values
  • Handle nullable account and transport values

Closes #3591380

Merge request reports