This commit consists of three classes of changes:
1) Changing various command main.go files to always behave as they
would have when features.BlockedKeyTable was true. Also changing
one test in the same manner.
2) Removing the BlockedKeyTable flag from configuration in config-next,
because the flag is already live.
3) Moving the BlockedKeyTable flag to the "deprecated" section of
features.go, and regenerating featureflag_strings.go.
A future change will remove the BlockedKeyTable flag (and other
similarly deprecated flags) from features.go entirely.
Fixes#4873
Aaron Gable