Why keep adding new flags in fixture?

[xhebox]

Feature Request

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

Describe the feature you'd like:

All default configs/flags of tidb/cdc/... are in the fixture package. And I always have very, very long list of cmd flags even if I am not using cdc or whatever.

I noticed that #162 refactored methods RecommendedCluster, and move them from their own packages into test_infra. Actually, why not move different variables in the fixture package back to different packages?

For example, tidb.NewCluster(opts...Options) in the tidb package, ticdc.NewCluster(WithImage(...)) in the ticdc package? You can include the most common flags in the suit package.

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[mahjonp]

I have noticed that, the refactor plan on fixture.go is on my schedule.