Bug 1833393 - New lint: check that all referenced pings are known

[badboy]

This introduces a new category of checks: those that run across both pings and metrics and can thus apply cross-checks.

Todo:

• Fix the types

[chutten]

r+wc

...though it occurs to me that now I'm going to be causing myself some grief in FOG since the organization of the GeneratedFile directives has us parsing the metrics yamls and pings yamls separately.

Oh well. Problem for future-chutten.

[badboy]

r+wc

...though it occurs to me that now I'm going to be causing myself some grief in FOG since the organization of the GeneratedFile directives has us parsing the metrics yamls and pings yamls separately.

Oh well. Problem for future-chutten.

Yeah, while implementing that I had the same thought.

[chutten]

r+wc
...though it occurs to me that now I'm going to be causing myself some grief in FOG since the organization of the GeneratedFile directives has us parsing the metrics yamls and pings yamls separately.
Oh well. Problem for future-chutten.

Yeah, while implementing that I had the same thought.

It'll be a good forcing function to complete the work Nika started in https://bugzilla.mozilla.org/show_bug.cgi?id=1686265 to reduce the number of times we're parsing these yamls.