Update opaque-keys library to use block_id for html_id for new keys.
Catch more places where get_children was giving us version aware references.
LMS-11237
Merge pull request #4966 from edx/split/html_id

Update opaque-keys library to use block_id for html_id for new keys.
Use opaque_keys w/ model vars not parsing of url
to generate url.
LMS-11209
JS regex's need to escape special chars
LMS-11260