Factor out typedb-common and typedb-proc-macro crates

[dmitrii-ubskii]

Problem to Solve

Currently the typeql crate provides declarative macros used for code generation (string_enum!, error_messages!) in its common submodule.

Proposed Solution

Replace declarative macros with more powerful and readable proc-macros (requires a separate crate).

Separate other common helpers into their own crate so as to have a clearer separation of domains at point of use.