Pm multiple binding issues fix

[dnenov]

Purpose

Addressing multiple binding issues that were failing inside the PackageManager. The PM should not generate these binding errors following this PR.

This PR cherry-picks and updates some of the changes from #14506. The old one will be closed in favor of multiple smaller PRs.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

• height offset conversion - removed
• AmbiguousMatchException - caused by the extended PackageManagerSearchElementViewModel hiding the Model property inside the base class. Renaming to SearchElementModel solved the issue
• refactor - created PackageManagerSearchElementViewModel property getters to allow the View to bind to the ViewModel, and not directly to the Model

Reviewers

@mjkkirschner
@reddyashish

FYIs

@Amoursol