Improve how the test-suite deals with exceptions

[edsko]

This also makes a few improvements to the make library itself:

• More consistent exceptions between the server and the client API: both now report a CallSetupFailure exception if the call cannot be established (though they use different definitions).
• Clients can specify initial compression algorithm, independent from the server (connInitCompression)
• The server will always support identity compression (unless using insist); see Negotation for details.
• If the server responds with an HTTP status other than 200, the response body will be included in the exception for easier debugging (@domenkozar, perhaps this is what you were asking about in https://github.com/well-typed/grapesy/issues/22#issuecomment-1936679862 ?)
• The server can insist on a compression algorithm, independent of what the client says (insist)
• Server handlers can now raise a GrpcException in the client by calling sendGrpcException instead by throwing this exception themselves; see sendGrpcException for discussion for the trade-off.

[edsko]

Verified that this still passes all interop tests (grapesy server, reference client in Java, C++, Go, and Python).