Rust SDK API follow-up: table accessor trait name change

[bfops]

The Rust SDK generates table accessor traits named trait FooTableAccess, whereas the module library generates trait foo. I initially thought we needed to generate the names in the SDK, but I believe that actually we can use the table name, provided we always convert it to snake_case rather than using the raw table name. Update the Rust SDK and the proposal to reflect this.

[bfops]

This is API breaking but we are leaving it as a P2 because it is not critical to get it into the 1.0 release.

[bfops]

(We didn't do this)