Define Language Agnostic Checks and Error Messages

[thealanjason]

Coming from UM-Bridge/UMBridge.jl#29 (comment)

In order to unify the experience of UMBridge across programming languages, it would be nice to have a language-agnostic reference for various checks(size, model features, etc) and their corresponding error messages.

[thealanjason]

Based on this reference, implementations can then be tested to correctly handle 0-based and 1-based indexing in client or server.