Move dependency from openapi-alps to azure-rest-api-specs

[mikeharder]

• Add @azure/openapi-diff to azure-rest-api-specs/package.json
• Update all code in openapi-alps to call npm exec --no -- oad compare instead of importing @azure/oad
• Publish openapi-alps, verify BreakingChanges still works
• Remove @azure/openapi-diff completely from openapi-alps

[konrad-jamrozik]

Update all code in openapi-alps to call npm exec --no -- oad compare instead of importing @azure/oad

Will it make somehow harder to pass arguments and capture output? Like, what if the code throws? We will have to manually parse exception from the stdout or stderr? I understand in case of API call this is easier.

For reference, this is an example API call right now:

    oadCompareOutput = await oad.compareTags(oldSpec, oldTag, newSpec, newTag, {
      consoleLogLevel: "warn",
    });

[konrad-jamrozik]

The only dependency on oad and/or openapi-diff in openapi-alps is in the Azure DevOps extension breaking-change.ts and its package.json.

[mikeharder]

Update all code in openapi-alps to call npm exec --no -- oad compare instead of importing @azure/oad

Will it make somehow harder to pass arguments and capture output? Like, what if the code throws? We will have to manually parse exception from the stdout or stderr? I understand in case of API call this is easier.

For reference, this is an example API call right now:

    oadCompareOutput = await oad.compareTags(oldSpec, oldTag, newSpec, newTag, {
      consoleLogLevel: "warn",
    });

I think our tools should move away from sharing code/APIs and towards sharing data over stdin/stdout. The https://en.wikipedia.org/wiki/Unix_philosophy. Because it allows interop between our own tools and third-party tools, and our own tools written in different langauges.

But either way, I think pinning the version of @azure/oad directly in azure-rest-api-specs will simplify updates enough to be worth any tradeoffs. It's one small step to getting everything out of openapi-alps.