Enables testing and bundling

[ufukty]

• resolves Testing #38
• resolves Bundle #35

[ufukty]

todo:

• maybe keep using mocha for integration testing along with the vitest used for unit tests
• sort .vscodeignore

[ufukty]

Integration test seems to fail at CI. Options are tricking the tester (with xvfb-run?), skipping integration tests in CI or removing integration tests completely in favor of only using unit tests.

Run npm run test-integration

> dim@3.2.0 test-integration
> npx tsc -p . && npx eslint src && node esbuild.mjs && vscode-test

- Resolving version...
✔ Validated version: 1.117.0
- Found at https://update.code.visualstudio.com/1.117.0/linux-x64/stable?released=true
✔ Found at https://update.code.visualstudio.com/1.117.0/linux-x64/stable?released=true
- Downloading (203.55 MB)
✔ Downloaded VS Code into /home/runner/work/dim/dim/.vscode-test/vscode-linux-x64-1.117.0
[2445:0422/105136.491777:ERROR:ui/ozone/platform/x11/ozone_platform_x11.cc:249] Missing X server or $DISPLAY
[2445:0422/105136.491827:ERROR:ui/aura/env.cc:257] The platform failed to initialize.  Exiting.
Exit code:   SIGSEGV
Error: Process completed with exit code 1.

Unit tests do look like would be enough for the significant portion of breaking changes. Integration tests can be added later.

[ufukty]

CI seems using an outdated Node version, doesn't meet the requirements of some Vitest dep.