Clean up RPL-related code

See merge request jvet/VVCSoftware_VTM!2473

Avoid use of std::iterator which is deprecated in C++17

See merge request jvet/VVCSoftware_VTM!2513

Avoid duplicating variables and functions for each reference list

Minor style improvements in AnnexBread

See merge request jvet/VVCSoftware_VTM!2514

Use standardized memory alignment features

See merge request jvet/VVCSoftware_VTM!2509

Minor cleanup for Slice.h

See merge request jvet/VVCSoftware_VTM!2511

Use strong-typed enum for deblocking's EdgeDir

See merge request jvet/VVCSoftware_VTM!2506

Fix and enable SIMD SSE functions

See merge request jvet/VVCSoftware_VTM!2498

Adapt code to new SW guidelines

See merge request jvet/VVCSoftware_VTM!2508

Changes include:
- use [[maybe_unused]] instead of cast to (void)
- use generic lambda function and remove related comment about C++11
- update MSVC version check
- don't condition '#pragma once' on MSVC version

JVET-AC0166: Set C++ version to C++17

See merge request jvet/VVCSoftware_VTM!2507

As decided with software style guide update.

Move GDR status out of PicHeader structure into Picture

See merge request jvet/VVCSoftware_VTM!2501

Virtual boundaries can be set in the encoder config without enabling GDR. The change makes sure, GDR constraints are conditioned on GDR being enabled.

- remove picture header allocations at the encoder
- use correct boundary location in reference pictures after removal of new PH

Should also fix memory allocation issues with PicHeader.

Remove macros from previous meeting cycle

See merge request jvet/VVCSoftware_VTM!2504