* fix(extension): explain an empty wildcard pool when no option has tags
* feat(wildcards): filter a wildcard's pool by a run-time variable
A $name term in a Pool filter or a reference filter reads the variable
when the prompt runs: options tagged with its value stay, options with no
tag in that value's group stay too. An unset variable or a value that is
no tag on the wildcard drops that term and files filter_variable_no_tag.
Constraints still apply on top. Stamps schema 11 (MAX_KNOWN 11).
* test(syntax): cover the filter variable helpers in the syntax suite
DumiFlex
6f089755fd