feat: support apexEmailNotification metadata

[scolladon]

Explain your changes

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Support ApexEmailNotification metadata, starting v49 to current latest version (v62)

Does this close any currently open issues?

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closes #933

[codeclimate]

Code Climate has analyzed commit 595f9ad and detected 0 issues on this pull request.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (653aaf9) to head (595f9ad).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #934   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           40        40           
  Lines         1083      1083           
  Branches       115       115           
=========================================
  Hits          1083      1083           

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[github-actions]

Shipped in release v5.48.0.
You can install the new version using the version number or the latest-rc channel

$ sfdx plugins:install sfdx-git-delta@latest-rc
$ sfdx plugins:install [email protected]

Happy incremental deployment!