Chore: Migrate to create-plugin

[jackw]

What this PR does / why we need it:
Migrates away from toolkit to create-plugin.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

[github-actions]

Levitate is-compatible report:

🔍 Resolving @grafana/data@latest...
🔍 Resolving @grafana/ui@latest...
🔍 Resolving @grafana/runtime@latest...
🔍 Resolving @grafana/e2e-selectors@latest...

🔬 Checking compatibility between ./src/module.ts and @grafana/data@9.3.6...
✔ Found @grafana/data version 8.4.11 locally

🔬 Checking compatibility between ./src/module.ts and @grafana/ui@9.3.6...
✔ Found @grafana/ui version 8.4.11 locally

🔬 Checking compatibility between ./src/module.ts and @grafana/runtime@9.3.6...
✔ Found @grafana/runtime version 8.4.11 locally

🔬 Checking compatibility between ./src/module.ts and @grafana/e2e-selectors@9.3.6...
✔ Found @grafana/e2e-selectors version 8.4.11 locally

✔️ ./src/module.ts appears to be compatible with @grafana/data,@grafana/ui,@grafana/runtime,@grafana/e2e-selectors

[iwysiu]

It currently fails the code coverage workflow because code coverage isn't available on main, thus it fails that step.

[idastambuk]

It currently fails the code coverage workflow because code coverage isn't available on main, thus it fails that step.

Is this the step that @fridgepoet merged a few days ago? If it is, maybe a rebase would be good to check if it all passes?

[fridgepoet]

@idastambuk I'll have a look and see if I can add the missing test coverage script to the package.json

[github-actions]

Backend code coverage report for PR #160
No changes

[github-actions]

Frontend code coverage report for PR #160

Plugin	Main	PR	Difference
src	8.98%	44.59%	35.61%