chore: migrate BeginDialog, ReplaceDialog to uischema

[yeze322]

Follows #1840 (pls review & merge #1840 before this PR)

Description

fixes #1770

Add uischema definition of BeginDialog / 'ReplaceDialog' and render it with UiSchemaRenderer.

Changes in uischema:

Task Item

fixes #1770

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code refactor (non-breaking change which improve code quality, clean up, add tests, etc)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Doc update (document update)

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have functionally tested my change

Screenshots

Please include screenshots or gifs if your PR include UX changes.

[yeze322]

merged to #1840