Converge sync and async resources

[dyladan]

Fixes: #3582

This PR makes it so that any resource detector can detect sync and async resources, returning both in a single resource object.

• Internally, the resource now stores all key/value pairs in a list. This means the override order comes from the order of detection, not the order of when the promises are resolved. Rejected promises are skipped. This should make the order of resource detection significantly more obvious to end users. It also paves the way for entities which explicitly require detection priority to be defined by the order in which entity detectors are configured.
• Resource detectors now return plain objects instead of new Resource instances. This should improve type compatibility in the future.
• Detected resource interface contains an optional attributes key, which all attributes are nested under. This will make it easier to extend for entities in the future by adding a new key to the object.

To be done in follow-up:

• [Resource] remove class and namespace export #5358
• [v2] Remove unstable resource detectors from resource package #5364

[pichlermarc]

Thank you for working on this 🙂
A quick preliminary review - I'll have a closer look at the implementation details next week :)

[codecov]

Codecov Report

Attention: Patch coverage is 85.16484% with 27 lines in your changes missing coverage. Please review.

Project coverage is 94.79%. Comparing base (f9fda8b) to head (ee3e732).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...lemetry-resources/src/detectors/BrowserDetector.ts	43.75%	9 Missing ⚠️
...ntelemetry-browser-detector/src/BrowserDetector.ts	0.00%	4 Missing ⚠️
...entelemetry-resources/src/detectors/EnvDetector.ts	93.87%	3 Missing ⚠️
...es/opentelemetry-resources/src/detect-resources.ts	80.00%	2 Missing ⚠️
...ntelemetry-resources/src/detectors/NoopDetector.ts	33.33%	2 Missing ⚠️
...tectors/platform/node/ServiceInstanceIdDetector.ts	33.33%	2 Missing ⚠️
packages/opentelemetry-resources/src/Resource.ts	97.87%	1 Missing ⚠️
...tors/platform/browser/ServiceInstanceIdDetector.ts	0.00%	1 Missing ⚠️
...ces/src/detectors/platform/node/ProcessDetector.ts	91.66%	1 Missing ⚠️
...rs/platform/node/machine-id/getMachineId-darwin.ts	66.66%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5350      +/-   ##
==========================================
+ Coverage   94.65%   94.79%   +0.13%     
==========================================
  Files         317      310       -7     
  Lines        8025     7967      -58     
  Branches     1687     1680       -7     
==========================================
- Hits         7596     7552      -44     
+ Misses        429      415      -14     

Files with missing lines	Coverage Δ
...imental/packages/opentelemetry-sdk-node/src/sdk.ts	96.03% <100.00%> (ø)
...ental/packages/opentelemetry-sdk-node/src/utils.ts	91.37% <100.00%> (ø)
...ges/opentelemetry-resources/src/detectors/index.ts	100.00% <100.00%> (ø)
...elemetry-resources/src/detectors/platform/index.ts	100.00% <100.00%> (ø)
...ources/src/detectors/platform/node/HostDetector.ts	100.00% <100.00%> (ø)
...esources/src/detectors/platform/node/OSDetector.ts	100.00% <100.00%> (ø)
...try-resources/src/detectors/platform/node/index.ts	100.00% <100.00%> (ø)
...ctors/platform/node/machine-id/getMachineId-bsd.ts	100.00% <100.00%> (ø)
...ors/platform/node/machine-id/getMachineId-linux.ts	100.00% <100.00%> (ø)
...ctors/platform/node/machine-id/getMachineId-win.ts	93.33% <100.00%> (ø)
... and 12 more

... and 1 file with indirect coverage changes

[chancancode]

Take it with an unhealthy amount of salt, but other than the suggestions I left (feel free to make your own judgment call), it looks good to me!

[trentm]

I think this LGTM.

I asked a Q at #5358 (comment)
I'm not totally clear on what the user's experience with resources (usage with the SDK I mean) will be after these changes at #5358, especially when Entities come along.