Add support for passing ksp options

[idanakav]

Resolves #1035

Sanity tested with:

cd examples/ksp ; bazel aquery 'mnemonic(KotlinKsp, //:coffee_lib)' | grep ksp_opts -A 2

    --ksp_opts \
    'arg1=value1' \
    'arg2=value2' \

[restingbull]

Does KSP fail if flags for absent plugins are passed?

[idanakav]

Does KSP fail if flags for absent plugins are passed?

No, those are generic KSP options that are going to be forwarded to any KSP processor. In other words, any KSP processor listed in the plugins will receive the same options.

[restingbull]

Does KSP fail if flags for absent plugins are passed?

No, those are generic KSP options that are going to be forwarded to any KSP processor. In other words, any KSP processor listed in the plugins will receive the same options.

Shoot. Going to need to track the plugin that needs the arguments.