[7.x] [canvas] Restore Workpad Title/button to Home; fix mounting behavior (#103601)

[kibanamachine]

Backports the following commits to 7.x:

• [canvas] Restore Workpad Title/button to Home; fix mounting behavior ([canvas] Restore Workpad Title/button to Home; fix mounting behavior #103601)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 8b4a53e
• Storybooks Preview
• Documentation Changes

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
canvas	1106	1104	-2

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
canvas	1.2MB	1.2MB	+348.0B

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
canvas	461.7KB	461.7KB	+1.0B

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @clintandrewhall