feat(mail): filter move folder dialog

[thefloatingleaf]

Title

feat(mail): filter move folder dialog

Body

Fixes #1488

What changed

• Adds a search field to the "Move message to folder" dialog.
• Filters move targets by folder name or full folder path.
• Keeps the existing exclusions for Drafts, Sent, and Templates.
• Shows an empty state when no folders match.
• Adds unit coverage for excluded folders, filtering, and selected folder closing.

Verification

• npm run lint -- --quiet
• ./node_modules/.bin/ng build runbox7
• ./node_modules/.bin/ng test runbox7 --watch=false --browsers=FirefoxHeadless --include='src/app/actions/movemessage.action.spec.ts'
  • The test bundle compiles, but execution is blocked locally because Firefox is not installed and Karma requires FIREFOX_BIN.
• Local dev server compiles and serves at http://127.0.0.1:4200/.

AI disclosure

This contribution was developed with assistance from OpenAI Codex in the local repository. The implementation and verification were reviewed before submission.