Picture Timing SEI is intentionally not used in parsing of frame field information SEI.

In the existing code retrieving the picture timing SEI from HRD could return a nullptr, when the SEI has
not arrived yet. The pointer is dereferenced without checking and passed into frame field info SEI parsing
function and used for a consistency check.

This refactoring moves the check after parsing of all SEI messages.

- fix two typos
- avoid global constant VCL_ASSOCIATED_SEI_LIST_SIZE

- fixes other style issues as well

Added syntax element display_elemental_periods_minus1 to the picture
timing SEI message
Check that the frame field information SEI message signals the same
value as the picture timing SEI message

Signalling of CPB timing parameters for sub-layers in DU-based HRD
operations
Remove pt_max_sub_layers_minus1 and use corresponding syntax element in
BP SEI
Make parsing of BP, PT and DUI SEI independent from SPS