chore(koa): migrate koa example to opentelemetry-instrumentation-koa

[haddasbronfman]

Which problem is this PR solving?

• Migrate examples for koa instrumentation: Migrate examples for koa instrumentation #950

Short description of the changes

• The koa examples were moved from ./examples/koa to ./plugins/node/opentelemetry-instrumentation-koa/examples

Checklist

• [ v] Ran npm run test-all-versions for the edited package(s) on the latest commit if applicable.

[codecov]

Codecov Report

Merging #1118 (f13cace) into main (44f9527) will increase coverage by 0.68%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1118      +/-   ##
==========================================
+ Coverage   96.07%   96.75%   +0.68%     
==========================================
  Files          14       24      +10     
  Lines         892     1234     +342     
  Branches      191      270      +79     
==========================================
+ Hits          857     1194     +337     
- Misses         35       40       +5     

Impacted Files	Coverage Δ
...trumentation-express/src/enums/ExpressLayerType.ts	100.00% <0.00%> (ø)
...opentelemetry-instrumentation-express/src/utils.ts	97.36% <0.00%> (ø)
...nstrumentation-express/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...ry-instrumentation-koa/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...opentelemetry-instrumentation-express/src/types.ts	100.00% <0.00%> (ø)
...tapackages/auto-instrumentations-node/src/utils.ts	98.00% <0.00%> (ø)
...ode/opentelemetry-instrumentation-koa/src/utils.ts	100.00% <0.00%> (ø)
...ode/opentelemetry-instrumentation-koa/src/types.ts	100.00% <0.00%> (ø)
...lemetry-instrumentation-koa/src/instrumentation.ts	97.53% <0.00%> (ø)
...try-instrumentation-express/src/instrumentation.ts	99.29% <0.00%> (ø)

[blumamir]

Thanks, left few minor comments.

The PR is marked as fix which will trigger a release of a new patch version for the instrumentation and will go into the changelog and release notes.
Since this PR only changes example files, it should be marked as chore which will not affect the release :)

[blumamir]

tracer name is usually set to a package name ( as set in the name field in package.json) which in our case is koa-example

[haddasbronfman]

Also here I took this behavior from here: https://github.com/open-telemetry/opentelemetry-js-contrib/pull/939/files, see tracer.ts file, line 50. this PR appears in the issue as a reference, so I thought this is ok they will be aligned.

[blumamir]

I think this is an overlooked mistake in express example PR.
This is a minor issue but would love other opinions @open-telemetry/javascript-approvers

[blumamir]

left a few last optional comments which are not blockers on my end.
Great work and thanks for taking this task and contributing :)

[blumamir]

I think this is an overlooked mistake in express example PR.
This is a minor issue but would love other opinions @open-telemetry/javascript-approvers

[blumamir]

Thank you for addressing everything! great job :)
LGTM