Fix assert() statement

See merge request !2538

Fixes an issue introduced in !2519

Clean up GDR condition checks

See merge request !2532

Fix parsing of unknown SEI message type.

See merge request !2536

JVET-AC0096: RPR functionality testing

See merge request !2534

When decoder parses SEI message of unknown type,
it does not add it to list of SEIs.

But then try to access it by calling back() of the list of SEIs.

If list is empty decoder crashes.

Otherwise (if list is not empty) decoder gets wrong SEI message (one of previously added to the list)

Possible fix is to make xReadSEImessage() and parseSEImessage() report if new SEI message object was added to the list

add options --SourceScalingRatio to rescale source video

See merge request !2522

Move MergeCtx and related classes from ContextModelling to InterPrediction

See merge request !2533

- use more const
- simplify some conditionals

JVET-AC0139: Unified merge function and updated cfg settings

See merge request !2518

Rename "LevelTier" to "TierLevel"

See merge request !2531

Ignore CLion files

See merge request !2530

Move parameter sets out of Slice.h/cpp

See merge request !2517

Include additional build with high bit depth enabled

See merge request !2529

Move initialisations to declaration for smaller PPS related classes. Define empty
constructors/destructors in header.

- manual reformatting:
  - try to shorten lines
  - keep blocks somewhat aligned
  - remove documentation comments
- make IBC flag bool
- add some braces
- add line breaks into longer functions
- move even longer functions into .cpp file
- move static variables and functions to the end

- move VPS and related classes into VideoParameterSet.h/cpp
- move SPS and related classes into SequenceParameterSet.h/cpp
- move PPS and related classes into PictureParameterSet.h/cpp
- rename ProfileLevelTier.h/cpp to ProfileTierLevel.h/cpp and move ProfileTierLevel class there

No other changes except for minor formatting/comment cleanup

Add GCC 12 to build configuration

See merge request !2528

Fix compilation when JVET_O0756_CALCULATE_HDRMETRICS is enabled

See merge request !2527

Define AlfMode element that captures enable flag and filter index

See merge request !2519

Having a single element reduces the number of data structures that
need to be maintained.