Remove macros before the integration of X meeting (one commit for each macro)

See merge request !2131

JVET-S0176 item5: constrain the value of sps_num_subpics_minus1 when SLI SEIs show up

JVET-T0055 item 2: Remove the step 9 of the general sub-bitstream extraction...

See merge request !1966

Fix for Ticket#1514 - Potential memory leak for m_sdiSEIInFirstAU and m_maiSEIInFirstAU

See merge request !2124

Fixes for multi-layer (spatial scalability) including fix for #1510

See merge request !2122

JVET-W0078: Multiview View Position SEI message

Fix #1509: lossless coding of RGB content

See merge request !2120

Fix reference picture list construction in case of inter-layer references (insert them before inactive references).

Align the QP of layer-1 picture with I-picture setting when B but only referring to an I picture of low layer (i.e. would be an I picture if layer was independent).

Align VTM with spec: fix inference value of pps_scaling_win_xxx_offset (equal to conformance window when not present).

Fix #1508: Use correct chroma format in call to verifyPlane

See merge request !2119

JVET-S0117 Virtual boundary rewriting for subpicture extraction

See merge request !2056

JVET-S0154 aspect9 and JVET-S0158 aspect4: bitstream extraction of extracting non-nested SEI from nested SEI

See merge request !1952