"title-prefix" constraint --> "required-title-prefix" for consistency, also add "required-label"

[dsyme]

Some safe outputs have the hard constraint

    title-prefix: "[bot] "      # require title prefix

and some have

    required-title-prefix: "[bot] "      # require title prefix

• We should use required-title-prefix throughout. Add codemod to help upgrade of existing workflows. The use of just title-prefix should be deprecated.

• None of this applies to cases where title-prefix is used to specify a title prefix to add to something that is being created, e.g. an issue or pull request.

• All safe outputs that have required-title-prefix should also have required-labels hard constraint. Existing labels: constraints should be renamed to required-labels: with codemode

• close-issue and close-pull-request and all other safe outputs that act on existing issues and pull requests should consistently have required-title-prefix and required-labels