feat: Update plugin to minimum Nx v16.8.1

[simondotm]

Migrated plugin workspace to Nx version 16.8.1
This was a key Nx release that introduced the as-provided and derived concepts for project name/directory.

I wanted to start the plugin compatibility roadmap here rather than just jump to the latest Nx, since there may be plugin users still using Nx 16.x and I want to give those users incremental Nx version updates of the plugin.

Plugin Changes:

• The plugin app and function generators now support the --projectNameAndRootFormat=[as-provided|derived] option, to match Nx's own plugins. This is only temporary until Nx 19, when all generators will use as-provided.
• Since new Nx workspaces default to as-provided this should make the plugin compatible with those scenarios.

e2e Changes:

• Split the e2e tests into smaller more maintainable modules
• e2e js lib tests now use the --bundler=tsc option instead of deprecated--buildable
• Nx e2e test runner seemed very unstable with this release, unless the Nx daemon is disabled.
  • Was seeing strange LOCK_FILE_CHANGED errors during e2e steps that installed new packages (eg. @nx/js:build)
  • Was seeing Nx complain that it couldnt find the newly generated projects in e2e tests
  • Solution was to set CI environment var for local e2e tests.
  • The e2e ensureNxProject() function does seem to run npm install at first as well as pnpm install so the e2e project workspace contains both package-lock.json and pnpm-lock.yaml files which is odd.
  • I experimented with later versions of Nx, and e2e tests seem to just use npm. So I'm not sure how the e2e runner determines if npm or pnpm gets used - either hard coded, or inferred from the e2e host project. Dont really care. 😅