[EME] Check support for full content type string (including codecs)

[asurdej-comcast]

When evaluating media capability support in EME::requestMediaKeySystemAccess(), MediaPlayer::supportsType() was called with only the container MIME type (e.g. 'video/mp4'), stripping codecs and other parameters.

Pass the full content type string (e.g. 'video/mp4; codecs="avc1.42E01E"') so the media engine can properly validate codec support, not just the container.
391b3c3

Build-Tests	Layout-Tests
✅ 🛠 wpe-246-amd64-build	✅ 🧪 wpe-246-amd64-layout
✅ 🛠 wpe-246-arm32-build	✅ 🧪 wpe-246-arm32-layout

[asurdej-comcast]

We received a test app from Dolby that queries support for dolby types from different JS APIs (isTypeSupported, MediaCapabilites, EME). With current implementation, EME will check only the mime type of original content type string. This ignores all parameters, including codecs.
According to spec comment

        // 3.13. If the user agent and implementation definitely support playback of encrypted media data for the
        //       combination of container, media types, robustness and local accumulated configuration in combination
        //       with restrictions:

"media types" here refers directly to codecs:

        // 3.9. Let media types be the set of codecs and codec constraints specified by parameters. The case-sensitivity
        //      of string comparisons is determined by the appropriate RFC or other specification.

In that sense it's reasonable to check full content type string instead of mime type only.

Checking the history of that impl shows that "codecs" was part of inital impl in 79099b3 (but was ignored by MediaPlayer at that time).
Then it was merged with mimeType into ContentType param in f73bc7e
and dropped eventually with e001f66