Initial MAUI support

[mattjohnsonpint]

Adding first set of projects for MAUI (see #1651).

• Captures unhandled exceptions from managed code only.
• Unit tests for UseSentry registration methods
• Sample app that throws an unhandled exception and sends to Sentry:

[mattjohnsonpint]

MAUI just went GA. I'll update and take one more pass at this before we merge.

[SimonCropp]

so the sample seems overly large for just demonstrating MAUI. eg can we remove the fonts, the image, aboutassets.txt, and any other stuff to trim it down

[SimonCropp]

can we remove the styles as well?

[mattjohnsonpint]

For now, I just want to use the sample app that comes with the MAUI default app template. We can trim it down later.

[mattjohnsonpint]

Something's broken with the sample app after updating to the MAUI GA. I'm investigating...

[mattjohnsonpint]

The Android app crashes immediately on startup if Sentry.csproj is compiled with the net6.0-android target. This worked in MAUI RC3, but isn't in GA. I'll investigate more tomorrow. For now, I've temporarily disabled that target so the sample app should stop crashing.

[mattjohnsonpint]

... That broke the Sentry.Samples.Android build, of course.

[SimonCropp]

i assume we want to disable this ?

[mattjohnsonpint]

i assume we want to disable this ?
...

Sure. I'll define that constant in the next MAUI update PR.