--apple_generate_dsym should also generate .symbols for upload to iTunes Connect

[brentleyjones]

Xcode allows for exporting symbols to allow iTunes Connect to symbolize crash reports, energy usage reports, and the metrics reports. Bazel currently doesn't support generating these symbols.

xcrun symbols should be called on each dSYM generated and packaged in a "Symbols" folder which is a sibling to the "Payload" folder:

xcrun symbols -noTextInSOD -noDaemon -arch all -symbolsPackageDir Symbols \
    bazel-bin/App/Sample.app.dSYM/Contents/Resources/DWARF/Sample_arm64 \
    bazel-bin/Extension/Extension.appx.dSYM/Contents/Resources/DWARF/Extension_arm64 \
    third_party/Framework.framework.dSYM/Contents/Resources/DWARF/Framework ...

It should also include the dSYMs for all embedded dynamic frameworks. This might require apple_dynamic_framework_import to take a new attribute that points to a dSYM.