build(deps): upgrade Angular to v20

[paulirwin]

This PR contains:

• bugfix
• feature
• refactor
• tests
• documentation
• others

Breaking Changes?

• yes
• no

Major version upgrade of Angular

Checklist

• commit messages follow the Conventional Commits pattern
  • A feature commit message is prefixed "feat:"
  • A bugfix commit message is prefixed "fix:"
  • A document related commit is prefixed "docs:"
• docs have been added / updated (for bug fixes / features)

Describe Your Changes

Upgrade Angular and necessary dependencies to Angular v20.

The non-package*.json changes were done automatically as part of the ng update migrations.

Does this PR affects any existing issues?

• yes
• no

Partial #636

[paulirwin]

Note that if anyone needs Angular 19 support (including as an intermediary step to 20/21), ngx-editor v19 should come out of beta before this is merged.

[rahulinaction]

Any timeline as to when this is getting merged ? Primarily waiting for the upgrade to v21

[ghosh81]

Note that if anyone needs Angular 19 support (including as an intermediary step to 20/21), ngx-editor v19 should come out of beta before this is merged.

When we can expect the release of ngx-editor v19? It is still in beta version. @paulirwin , @sibiraj-s