Add function group to metadata and sync triggers

[jviau]

Issue describing the changes in this PR

resolves #9732

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• My changes do not require diagnostic events changes
  • Otherwise: I have added/updated all related diagnostic events and their documentation (Documentation issue linked to PR)
• I have added all required tests (Unit tests, E2E tests)

Additional information

This PR adds function grouping calculation as an extension method FunctionMetadata.GetFunctonGroup(). Function grouping is included in sync-triggers payload if it is non-null. Function grouping calculation works as follows:

1. If FunctionMetadata.Properties["FunctionGroup"] is present, return that.
2. Else, check if HTTP or Durable trigger. Return http or durable respectively.
3. Return null if none of the above checks succeed.

Some additional changes include binding & function metadata extensions refactoring.