feat(alerts): enable tab selection for dashboard alerts/reports

[fisjac]

SUMMARY

Implements a new feature enabling a tab to be selected as a view for an alert/report. When a dashboard is selected as the content for a report, an antd TreeSelect component is rendered to load and select tab options. When selected, the tab selection is added to the report payload as an anchor.

On execution, the feature takes advantage of existing logic for the report.extra.dashboard.anchor_tab attribute of the ReportSchedule SQLA model. When extra metadata are attached to the report schedule, a permalink is generated with the metadata included, and this permalink is then used to generate screenshots of the selected dashboard.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

ADDITIONAL INFORMATION

• [ ] Has associated issue:
• [x] Required feature flags: ALERT_REPORTS, ALERT_REPORT_TABS
• [x] Changes UI
• [ ] Includes DB Migration (follow approval process in SIP-59)
  • [ ] Migration is atomic, supports rollback & is backwards-compatible
  • [ ] Confirm DB migration upgrade and downgrade tested
  • [ ] Runtime estimates and downtime expectations provided
• [x] Introduces new feature or API
• [ ] Removes existing feature or API