source level filter support

[csuzhangxc]

Feature Request

Is your feature request related to a problem? Please describe:

run many tasks for the same MySQL source and an incompatible DDL applied in the source.

Describe the feature you'd like:

now, we need to add a filter rule for this incompatible DDL in all tasks' config.

but if we can only add a filter for all (sub)tasks with this source, it's easier to use.

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: