layers:Migrate to new validation error IDs

layers:Migrate to new validation error IDs

Migrate valid usage IDs to new numbers based on the string IDs that are
integrated into the spec build process.

The formula for mapping the string ID to the new VALIDATION_ERROR enum
value is in vuid_mapping.py script.
The mapping between the old IDs and the new IDs is in the file
"old_vuid_to_new_mapping.txt."

The vk_validation_error_database.txt file has the new IDs as well as
the string-based ID for each element and a column indicating if the
valid usage is in the core spec or if it requires extension(s) and is
therefore in the extension spec.

The error messages were shortened and no longer include a section
reference. Now the link goes directly to the line in the spec where
the valid usage text occurs. The base of the spec link is the core spec
unless the VU requires an extension in which case the spec with all
extensions is used as the base.