Add dashboard-as-code functionality

[JCZuurmond]

Initial version that covers functionality for ucx.

This is a big PR staged to resolve #138. It was broken in multiple smaller PR into this feature branch (see links int the commits). The feature branch allows for reviewing of the dashboard as code functionality.

• [x] Resolves #141
• [x] Resolves #112
• [x] Resolves #130
• [x] Resolves #131
• [x] Resolves #148
• [x] Resolves #133
• [x] Resolves #135
• [x] Resolves #202
• [x] Resolves #137
• [x] Resolves #110
• [x] Resolves #114
• [x] Resolves #158
• [x] Resolves #159
• [x] Resolves #163
• [x] Resolves #165
• [x] Resolves #169
• [x] Resolves #175
• [x] Resolves #187
• [x] Resolves #191
• [x] Resolves #200
• [x] Resolves #180
• [x] Resolves #157
• [x] Partially resolves #134

[github-actions[bot]]

This PR breaks backwards compatibility for databrickslabs/ucx downstream. See build logs for more details.

_{Running from downstreams #256}

[github-actions[bot]]

✅ 35/35 passed, 2 skipped, 9m4s total

_{Running from acceptance #277}