PalmCivet should give two different exceptions

[ericpromislow]

1. Emit InvalidByteQuantityError for an invalid or missing suffix

2. Emit InvalidNumericSequence if the value does not start with a number.

RIght now we just get InvalidByteQuantityError for all strings, and then the error messages are incorrect.

[tcdowney]

This would allow us to avoid doing this:
https://github.com/cloudfoundry/cloud_controller_ng/blob/3a1b20a1098d054e876a23bb1c8a8a9f314ed167/lib/cloud_controller/app_manifest/byte_converter.rb#L10