Plugin V2 (#116)

[simondotm]

TODO

• [x] Provide function generator
• [x] Update application generator
• [x] Update documentation
• [x] Fix e2e tests
• [x] Test that use of app implicitDependencies does the right thing
• [x] Test that function deploy calling app deploy does the right thing
• [x] Provide generator to change --project for a firebase app
• [ ] Support --productionProject for a firebase app
• [x] Provide generator to remove or rename a function
• [x] Provide generator to migrate workspace from v1 plugin schema
• [x] Remove application executor
• [x] Use firebase app directory for functions if not specified
• [x] Make sure @nx/esbuild is added as a plugin dependency
• [x] esbuild format setting can always be esm even if source libraries are commonjs?
• [ ] Provide npm script to serve application (workaround for Nx not handling SIGINT properly)