Update ts-migrate-server to pass back a list of migrated files

[NickHeiner]

Part of #168

[NickHeiner]

Hmm – when I run yarn test locally, I get:

ts-migrate: PASS tests/commands/migrate/migrate.test.ts (10.485 s)

However, in the GH Actions output, I see:

ts-migrate: FAIL tests/commands/migrate/migrate.test.ts (6.248 s)

Curiously, it looks like the GH Action ran against the test file from main, not my PR:

ts-migrate:   ● migrate command › Migrates project
ts-migrate:     expect(received).toBe(expected) // Object.is equality
ts-migrate:     Expected: 0
ts-migrate:     Received: {"exitCode": 0, "updatedSourceFiles": Set {"/home/runner/work/ts-migrate/ts-migrate/packages/ts-migrate/tests/tmp/ts-migrate-bi79QG/Foo.tsx", "/home/runner/work/ts-migrate/ts-migrate/packages/ts-migrate/tests/tmp/ts-migrate-bi79QG/file-1.ts"}}
ts-migrate:       33 |     const [rootData, outputData] = getDirData(rootDir, outputDir);
ts-migrate:       34 |     expect(rootData).toEqual(outputData);
ts-migrate:     > 35 |     expect(exitCode).toBe(0);
ts-migrate:          |                      ^
ts-migrate:       36 |   }, 10000);
ts-migrate:       37 | });
ts-migrate:       38 |
ts-migrate:       at Object.<anonymous> (tests/commands/migrate/migrate.test.ts:35:22)

Have you seen something like this before? Maybe I'm missing something silly. I can investigate more later.

[Rudeg]

@NickHeiner Sorry for the delay!
You missed one test in the ts-migrate main package. Updated and will merge after the build :)