[CLI] Watcher should only run generates task if changed files are watched

### Is your feature request related to a problem? Please describe.

Currently, when any watched file is changed, Codegen runs all generate tasks.
And since all generate tasks must be completed at the same time, one slow task can hold up the whole thread.

### Describe the solution you'd like

A changed file should only trigger generate tasks that watch it.

### Describe alternatives you've considered

Splitting the Codegen config to multiple files and run `concurrently` to manage the flow i.e. manually orchestrate the flow.
However, it would be good if Codegen can handle it.

### Any additional important details?

_No response_