Diagnostics CLI: Add "Success" output message when no errors found

Currently, the CLI diagnostics command does not return output when no warnings or errors are found. Example:

$ yarn rw diagnostics
yarn run v1.22.4
$ /Users/price/Repos/create-redwood-app/node_modules/.bin/rw diagnostics
✨  Done in 3.07s.

This can cause confusion as to whether anything was run at all and if the project is ok. Improved output may include:

• count of checks run/completed
• count of warnings found
• count of errors found
• 🏆 if everything is good

[M0nica]

I think implementing these enhancements could be implemented between four tickets (1) improve the success state by making it more clear, 2) reformatting the CLI output, and 3 + 4)enhancing the diagnostics to include Prisma and TypeScript checks which could be worked on concurrently).

1. updating the check/diagnostics CLI to output something along the lines of “Nothing to see here!” when there are no warnings or errors.
2. update and reformat the current CLI output to have Redwood Core Diagnostics and then print out the individual warnings/errors. I am assuming GraphQL - but not necessarily Prisma, environment, routes, router, SDL files, service functions, TOML, the existing diagnostics in redwood/redwood all would fall under Redwood Core Diagnostics.

$ rw check
... 
[task output]
[task output]
etc
...

SUMMARY
- **Redwood Core Diagnostics** [2 Warnings, 1 Error]
  - _warning_: Your env vars are missing
  - _warning_: Name your queries
  - _error_: missing redwood.toml

1. Update check/diagnostics CLI to integrate with TSC and output any of those errors. Would we want to also allow TSC warnings to print in addition to errors and or for the level that outputs to be configurable by the user?

$ rw check
... 
[task output]
[task output]
etc
...

SUMMARY
- **Redwood Core Diagnostics** [2 Warnings, 1 Error]
  - _warning_: Your env vars are missing
  - _warning_: Name your queries
  - _error_: missing redwood.toml
- **Typescript** [1 Warning]
  - _warning_: gratuitous use of 'any'

1. Update check/diagnostics CLI to integrate with Prisma linting (I am not sure how straightforward this type of integration is 🤔)

... 
[task output]
[task output]
etc
...

SUMMARY
- **Redwood Core Diagnostics** [2 Warnings, 1 Error]
  - _warning_: Your env vars are missing
  - _warning_: Name your queries
  - _error_: missing redwood.toml
- **Prisma** [All Good]

[jtoar]

From a quick read it sounds like this was implemented but there’s still some good ideas here so I won’t close it outright just yet