Enhancement: Quoting/escaping for SOQL values and external IDs

To effectively use query() at all or use external IDs with upsert() or get(), quoting/escaping must be applied. Think it would be good for this to be built into the library, either as helpers or built into these functions. Otherwise it has to be redone in every implementation.

Willing to contribute a PR. Helpers would be easy… looks like building into query() would be possible though it already uses **kwargs for something else so it would need to be a specific named argument.