feat: Add experimental rewrite of go2rtc live provider (MSE/WebRTC/MP4/MJPEG) (#2580)

- Closes #2556
- Closes #2450

**Key intended features:**
 - go2rtc compatible
- 100% test coverage to significantly improve ability to test, maintain
and work around browser weirdnesses (e.g. Safari).
 - Written from the ground up in the style of the rest of the project.

**To use:**
 - Change `live_provider` from `go2rtc` to `go2rtc-experimental`.

tests/components-lib/live/providers/go2rtc-experimental/utils/webrtc-sdp.test.ts

@@ -0,0 +1,13 @@
+import { describe, expect, it } from 'vitest';
+
+import { sdpHasH265 } from '../../../../../../src/components-lib/live/providers/go2rtc-experimental/utils/webrtc-sdp';
+
+describe('sdpHasH265', () => {
+  it('should detect an H.265 rtpmap', () => {
+    expect(sdpHasH265('a=rtpmap:98 H265/90000\r\n')).toBe(true);
+  });
+
+  it('should return false without an H.265 rtpmap', () => {
+    expect(sdpHasH265('a=rtpmap:96 H264/90000\r\n')).toBe(false);
+  });
+});