Miscellaneous fixes (#22924)

* apply annotation offset to frigate+ submission frame time

* fix broken docs links with hash fragments that resolve wrong on reload

* undo

* use recording snapshot for frigate+ frame submission from VideoControls

rather than a canvas grab/paint, which may not always align with an ffmpeg snapshot due to keyframes

* add more docs links

- display docs link for main sections on collapsible fields

* dialog button consistency