Ts project refs: Migrates Upgrade Assistant to a TS project

[TinaHeiligers]

Summary

Partially addresses #89321

Partial stats from running node --max-old-space-size=4096 ./node_modules/.bin/tsc -p x-pack/tsconfig.json --extendedDiagnostics --noEmit:

Before:
Files: 14891
Lines: 1609898

After:
Files: 14783
Lines: 1597047

[TinaHeiligers]

@sebelga I ran the flaky test several times locally and it passes every time. Do you happen to know why the order here matters?

stack trace:

Error: expected [ 'Advanced Settings [8.0.0-SNAPSHOT]',
  'Advanced Settings [6.0.0]',
  'A Dashboard',
  'logstash-*',
  'A Pie' ] to sort of equal [ 'Advanced Settings [6.0.0]',
  'Advanced Settings [8.0.0-SNAPSHOT]',
  'A Dashboard',
  'logstash-*',
  'A Pie' ]
    at Assertion.assert (/dev/shm/workspace/parallel/12/kibana/packages/kbn-expect/expect.js:100:11)
    at Assertion.eql (/dev/shm/workspace/parallel/12/kibana/packages/kbn-expect/expect.js:244:8)
    at Context.<anonymous> (test/functional/apps/saved_objects_management/feature_controls/saved_objects_management_security.ts:189:30)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at Object.apply (/dev/shm/workspace/parallel/12/kibana/packages/kbn-test/src/functional_test_runner/lib/mocha/wrap_function.js:73:16) {
  actual: '[\n' +
    '  "Advanced Settings [8.0.0-SNAPSHOT]"\n' +
    '  "Advanced Settings [6.0.0]"\n' +
    '  "A Dashboard"\n' +
    '  "logstash-*"\n' +
    '  "A Pie"\n' +
    ']',
  expected: '[\n' +
    '  "Advanced Settings [6.0.0]"\n' +
    '  "Advanced Settings [8.0.0-SNAPSHOT]"\n' +
    '  "A Dashboard"\n' +
    '  "logstash-*"\n' +
    '  "A Pie"\n' +
    ']',
  showDiff: true
}

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[rudolf]

@TinaHeiligers the flaky test is my fault (v2 migrations) and should be fixed if you merge in master since v2 migrations have been disabled again in master tests.

[jloleysens]

Code changes look good to me, happy to merge when CI is done 👍🏻

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: e823b9d

Metrics [docs]

✅ unchanged

History

• 💛 Build #102838 was flaky ccc3bb5
• 💔 Build #102829 failed 1199826
• 💔 Build #102818 failed 507ce3d

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream