feat: individual settings to control user interaction

[Danielku15]

Issues

Fixes #2666

Proposed changes

Splitup of the central enableUserInteraction into more fine grained options.

• enableSeekToClick controls whether a simple click scrubs the player to the beat at the clicked location
• enablePlaybackRangeSelection controls whether a click+drag draws a user selection which defines the selected playback range.
• bonus feature: resetPlaybackRangeOnClick controls whether a simple click clears the current selection. This is useful if a custom "clear" GUI button is shown. Allows the user to seek while keeping the selection.

Edge cases:

• When having a selection and clicking to seek, we clamp the playback cursor to the playback range (e.g. clicking on a beat before the range, seeks to the start of the playback range).
• We now only draw a new selection range if the user really click+drags to a full new selection spanning at least 2 beats. This prevents accidental clearing of the selection if you just click and drag a few pixels.

Overall this allows a more static playback range selection control:

1. only allow drag selection based on custom UI (e.g. coupling it to looping, or asking the user explicitly to select a range after selecting the respective UI item)
2. keep the user selection active and allowing seeking while the range is fixed. clearing via custom UI element.

Checklist

• I consent that this change becomes part of alphaTab under it's current or any future open source license
• Changes are implemented
• New tests were added

Further details

• This is a breaking change
• This change will require update of the documentation/website