fix(jest-utils,nx-plugin): Fix running jest config, test:cov nx configuration, and path resolution in tests

[luxaritas]

Few things this addresses:

• Jest requires ts-node to use ts configuration files. This is now added in the relevant generator
• Jest currently forces ts configuration files to be compiled as CJS. This means we have to compile jest-utils as CJS, as otherwise we won't be able to import it (as you can't require ESM from CJS). See [Feature]: Support loading jest.config.ts as ESM jestjs/jest#13118
• Only test was properly set up with nx (caching/dependencies/inputs/outputs), test:cov now is as well

[luxaritas]

As a note: I am up for discussion about whether we really want to require ts-node (ie, adding extra dependencies just for the config file). On a brief test, it does appear that we're getting proper autocomplete on JS files in VSC since it's able to pick up on the types from jest-utils, and we could just add // @ts-check to force the editor to report type errors

[luxaritas]

After discussion, we've agreed that there's not really a benefit for adding ts-node - we'll stick with js configs and // @ts-check. I'll also probably work on #119 in this PR as well so that all the config changes are centralized

[luxaritas]

So using a root config was a bust, but I realized something else - if we had something like

src/
  mod/
      mod.ts
  index.ts

and index.ts imported 'mod/mod', running a jest test importing index would throw a module resolution error. I had to explicitly set both the baseUrl in the spec tsconfig (so the TS compiler would see it) and the modulePaths property in the jest config (so that jest knows how to resolve it). The mechanism I'm using to resolve the tsconfig to look in for the baseUrl isn't perfectly robust vs how jest allows you to set configuration, but I think it's the best effort we can do.