Add STAT table, fix name IDs, suppress font-synthesis, add fvar instance #22392
Concluding from the discussion in #22355 name ids should have values
Fixes #22355 for Firefox.
Concluding from the discussion in #22355 name ids should have values greater than 255, and the font should have a STAT table. The name id issue is something the Firefox prints out as an error on the command line. Add a STAT table, add a named instance for the regular instance, and move name ids in this change. Also add encoding headers in tests and references, and suppress font-synthesis as this is needed to help the test pass on Firefox. Fixes #22355 for Firefox.