feat(flags): add javascript onboarding

[michellewzhang]

adds javascript onboarding to the feature flag sidebar. also, if we detect that event.contexts.flags is not undefined, we hide the first half of the onboarding as specified in the designs

updated copy

no integration yet

https://github.com/user-attachments/assets/3fd3eade-aac4-4635-9fc9-ab5a71886651

integration detected

https://github.com/user-attachments/assets/7c42a145-2a03-40ab-b066-279edeeed140

• relates to https://github.com/getsentry/team-replay/issues/502?reload=1?reload=1

todo:

• [x] analytics charts
• [ ] figure out CTA details (another way the sidebar can be triggered)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 40.62500% with 19 lines in your changes missing coverage. Please review.

:white_check_mark: All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...ents/featureFlags/featureFlagOnboardingSidebar.tsx	0.00%	6 Missing :warning:
...s/events/featureFlags/useFeatureFlagOnboarding.tsx	50.00%	5 Missing :warning:
...vents/featureFlags/featureFlagOnboardingLayout.tsx	0.00%	4 Missing :warning:
...c/app/gettingStartedDocs/javascript/javascript.tsx	33.33%	4 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #81078 +/- ## ========================================== - Coverage 80.33% 78.45% -1.89% ========================================== Files 7223 7220 -3 Lines 320085 319799 -286 Branches 20778 44045 +23267 ========================================== - Hits 257156 250888 -6268 + Misses 62536 62532 -4 - Partials 393 6379 +5986 ```

[codecov[bot]]

Bundle Report

Changes will increase total bundle size by 6.22kB (0.02%) :arrow_up:. This is within the configured threshold :white_check_mark:

Detailed changes

| Bundle name | Size | Change | | ----------- | ---- | ------ | | app-webpack-bundle-array-push | 31.96MB | 6.22kB (0.02%) :arrow_up: |