test: sample app feature flag improvements

[armcknight]

Originally in this PR:

• restart sdk on reconfig: I borrowed the idea @philprime had to close and restart the SDK whenever changing a config option, moving it to SentrySDKOverrides and using it in the Camera sample app. There weren't yet config overrides for isSessionReplayEnabled or isViewRendererV2Enabled, they are coming in test: more override config #5201

Merged into this PR:

• in app debug menu: instead of a button in the Extras tab of iOS-Swift only, add a floating debug menu button that can display the feature flag list view from anywhere in any sample app (iOS-only for now) (merged in from test: iOS sample app debug menu #5222)
• DSN view in debug menu: instead of only showing the DSN viewer/changer in a handful of views in iOS-Swift, put it in the debug menu so it's accessible from anywhere in any sample app (again, iOS-only for now) (merged in from test: DSN view in debug menu #5228)

#skip-changelog

[philprime]

Would it be possible to merge the individual PRs directly into main for future PRs?
I am not sure what to review here as I did review the other PRs already.

[armcknight]

@philprime This is not that large of a PR and it's for sample apps, just review the whole thing. I also explained the changes in the description. You don't need to go through this with a fine toothed comb, do the sample apps do what the changes suggest?

[philprime]

I just noticed the same compilation issue occured in #5201 (review) and got fixed there. So I assume it will be fixed in this PR as soon as the #5201 is merged.