Break up the ubrn command line build commands

[jhugman]

According to The Big O of Code Reviews, this is a O(n) change.

This adds a number of suppression flags to the command line. This is to make it:

• easier to generate code using your own build process
• easier to customize parts of the build process
• cache as much as possible of the previous build

For build ios:

• --no-xcodebuild suppress the creation of an xcframework. The xcframework is expected, but with this flag, you are expected to provide it; perhaps after generating swift from a library file. (future work idea: add an arg to generate Swift from uniffi).
• --no-cargo detects if any targets are already built, and uses that to generate library files. If no targets are built, then build all, re-using the library files next time.

For build android

• --no-jniLibs, this is Android reflection of --no-xcodebuild. I'm not sure what this would be used for.
• --no-cargo detects if any targets are already built, and uses that to generate library files. If no targets are built, then build all, re-using the library files next time.

A new command: generate all --config config.yaml lib.a:

• This combines generate bindings and generate turbo-module into a higher level command which accepts a config file and a pre-built library file.

[zzorba]

LGTM, appreciate the increased granularity here.