rust: derive clone

[silverjam]

So we can have a way to easily detach message objects from their source lifetimes, implement clone.
This enables us to implement something like:

https://gist.github.com/silverjam/43b543c58f37cb39575b01487f10779e

[jbangelo]

I don't think there are any other traits we'd like to automatically derive for all messages? List: https://doc.rust-lang.org/stable/rust-by-example/trait/derive.html

[silverjam]

@jbangelo nothing jumps out at me, except maybe we should be Copy instead of Clone? I picked .clone() since it's more explicit, and SBP structs can be 256 bytes (not sure what the threshold should be for picking copy over clone w.r.t. memory size). In support of copy: SBP messages have a fixed maximum size, and we don't contain anything that's not copy-able. Not in support of copy: structs can be large-ish.

[jbangelo]

@silverjam I think the log message contains a string (others might as well), which would prevent deriving Copy for it. I think only deriving Clone is probably good enough. Given the variable size of the messages I don't think it's in the spirit of the Copy trait too potentially be copying 255 bytes.