1999421 - Merge instances of creation of metric type IDs in `js.py` and `util.py` into one method

Status: NEW

(Toolkit :: Telemetry, enhancement, P2)

Description

[Charlie Humphreys [:charlie] [:jeddai]]

Both write_metrics in toolkit/components/glean/build_scripts/glean_parser_ext/js.py and type_ids_and_categories in toolkit/components/glean/build_scripts/glean_parser_ext/util.py iterate over the objects to obtain the list of metrics used in a build and generate type ids from those metrics. The way in which each method generates those ids has to be kept in sync whenever one of them needs to be updated, like when Bug 1998248 necessitated changes to make sure the ordering of types was consistent across builds (because they were being written to the JS CPP header file).

This bug calls for merging the contents of both methods, such that a single method exists for this moving forward.