chore: generate non-cloud client library (#1770)

[gcf-owl-bot[bot]]

• chore: add proto group prefix

• add test case for generating google maps

• run new tests in ci

• parameterize group id for proto artifacts

• use helper to compute group id of proto artifacts

• verify non cloud library generation

• change artifact name in golden

• restore new client test

• change description

• change description

• add comments to _proto_group_id Source-Link: https://github.com/googleapis/synthtool/commit/269a915036d3523ad357af5af597a8b0f0f783cc Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-java:latest@sha256:9bf82029163bc06d58f56682afd1893a42ace3e04b0359accb86f79c6ecdc9f9