bootstrap TiCDC servers with the TiUP's default data-dir configuration

[zhaoxinyu]

Feature Request

Is your feature request related to a problem? Please describe:
At present, TiUP playground bootstraps TiCDC server without --data-dir option, so TiCDC employs /tmp/cdc_data as its working directory, which may results in confusion to users.

Describe the feature you'd like:
Use the default $HOME/.tiup dir as TiCDC's data directory.

Why the featue is needed:
It could provide a consistent user experience if the data of TiCDC is stored in the default TiUP dir.

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[zhaoxinyu]

/assign @nexustar