fix(rush): add appropriate path-mapping, add sourcemaps for dev

[danwbyrne]

Description of the Change

Previously I had just set the tsconfig used in every package to use build @neo-one packages as opposed to including their sources in the compilation (this makes more since with the incremental building we do now).

The issue with this is in the dev environment clicking through type definitions brought you to lib/path/to/types.d.ts as opposed to where you really want to go to which is src/path/to/types.ts.

The solution to this is adding the path mapping we used in the lerna version of neo-one

{
  "paths": {
      "@neo-one/*": ["../neo-one-*/src"]
  }
}

which we were already doing for jest tests since source maps weren't included yet.

To make jest faster and give us proper source-mapping on errors I've added source-mapping to the buildTypescript task. These sourcemaps are NOT shipped when using rush pack, they are just used in the dev environment and fortunately they "just worked" with jest after they were generated.

Test Plan

I tested this by making a test in a package which expected a function imported from another package to not error, and then making that function error. In the old version without sourcemaps we would not get proper stack traces, after implementing source maps all of the stack traces reference source code.

Benefits

Adding sourcemap support for jest decreased total test time from ~350s to ~300s while also providing more information than before.

Our tsconfig structure is a bit confusing, but the basic pattern so far is to have every package use @neo-one/build-tools/includes/tsconfig.dev.json and then individual processes such as rush build or rush test use their own tsconfig with the @neo-one/* path removed.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (rush@980af2a). Click here to learn what that means.
The diff coverage is 0%.

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Flag	Coverage Δ
#true	27.48% <0%> (?)

Impacted Files	Coverage Δ
.../neo-one-build-tools/src/builds/buildTypescript.ts	0% <0%> (ø)
packages/neo-one-build-tools/src/build.ts	0% <0%> (ø)
packages/neo-one-build-tools/src/publish.ts	0% <0%> (ø)
...ackages/neo-one-build-tools/src/builds/buildBin.ts	0% <0%> (ø)