PoC: Configuration\CompositeResolver and SPI discovery

[ChrisLightfootWild]

Proof of concept, to cover the use-case where multi-application installs operate on shared-infra and wish to provide their own configuration.

See #1436.

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Any suggestions on the best way to approach adding tests for these optional dependencies?

EDIT: I added a test. It's not my proudest moment, but I can't think of another way to beat the way the SDK currently bootstraps and triggers Configuration setup so early on. We could modify the CompositeResolver to allow it's static instance to be reset - but that would be a change which was made purely to improve testability.

[ChrisLightfootWild]

Hey @Nevay 👋

Speaking with @brettmc and he says you had some comments on .env processing n the past here. I did not recall this before throwing this together, apologies!

Do you have any concerns with delegating .env processing to the appropriately available packages via SPI?

[Nevay]

No, I was only concerned about implementing our own .env parsing.

[codecov]

Codecov Report

❌ Patch coverage is 3.63636% with 53 lines in your changes missing coverage. Please review.
✅ Project coverage is 68.28%. Comparing base (e54a43d) to head (40acb23).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...onfiguration/Resolver/SdkConfigurationResolver.php	0.00%	11 Missing ⚠️
src/Config/SDK/Configuration.php	0.00%	10 Missing ⚠️
src/Config/SDK/Instrumentation.php	0.00%	10 Missing ⚠️
...tion/Environment/Adapter/SymfonyDotenvProvider.php	0.00%	9 Missing ⚠️
...on/Environment/Adapter/VlucasPhpdotenvProvider.php	0.00%	7 Missing ⚠️
...ig/SDK/Configuration/Environment/LazyEnvSource.php	0.00%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1523      +/-   ##
============================================
- Coverage     68.76%   68.28%   -0.48%     
- Complexity     2857     2868      +11     
============================================
  Files           425      429       +4     
  Lines          8704     8740      +36     
============================================
- Hits           5985     5968      -17     
- Misses         2719     2772      +53     

Flag	Coverage Δ
8.1	?
8.2	?
8.3	?
8.4	?
8.5	68.28% <3.63%> (-0.28%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ommon/Configuration/Resolver/CompositeResolver.php	100.00% <100.00%> (ø)
...mon/Configuration/Resolver/EnvironmentResolver.php	100.00% <100.00%> (ø)
...K/Common/Configuration/Resolver/PhpIniResolver.php	100.00% <ø> (ø)
...ig/SDK/Configuration/Environment/LazyEnvSource.php	0.00% <0.00%> (ø)
...on/Environment/Adapter/VlucasPhpdotenvProvider.php	0.00% <0.00%> (ø)
...tion/Environment/Adapter/SymfonyDotenvProvider.php	0.00% <0.00%> (ø)
src/Config/SDK/Configuration.php	0.00% <0.00%> (ø)
src/Config/SDK/Instrumentation.php	0.00% <0.00%> (ø)
...onfiguration/Resolver/SdkConfigurationResolver.php	0.00% <0.00%> (ø)

... and 6 files with indirect coverage changes

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[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[brettmc]

This looks pretty solid now, would you like to rebase and we can get it merged @ChrisLightfootWild ?