Feature/description support fields length 1000 (#1267)

Feature/description support fields length 1000 (#1267)

* fix migrations to not use config constant values as it can introduce bugs later when they change; (fixes #1259)
remove constant fields imports from migrations

* add migrations to update description and support fields to 1000 (fixes #1258)

* fix client/server account and video_channel description/support fields to be max len 1000 (fixes #1258);
fix test Should fail with a too long description;
fix test Should fail with a long description;
fix test Should fail with a long description;
Remove USER.SUPPORT from constants since that field no longer exists;
null not false, in migrations/0280-description-support.ts;
video support field 1000, oops;

* rename migration 0280-description-support.ts -> 0285-description-support.ts;
update video support maxlength text