Upgrade proto compilation script to work with newest version of buf

[philipjames44]

Buf version 0.48.2 (https://github.com/bufbuild/buf/releases/tag/v0.48.2) is the highest confirmed working version to compile proto files using ./scripts/protocgen.sh; at the moment, to install this version a manual buf installation from source is required.

As of writing this ticket, buf is currently on release 1.7.0 so we are considerably behind the latest release.

The goal of this ticket should be to investigate if we actually want buf as a depencency, and either update the script to work with the most recent version of buf, or remove it entirely from the script.

Note: Regardless of buf version changes, the protoc-gen-grpc-gateway plugin will also have to be upgraded to v2. Our current script assumes v1 which is out of date and must be force installed.