feat: add IAM credentials authentication

[liramon1]

The identity LSP was changed to load and save IAM profile kinds.

Problem

Flare only provides bare-bones support for IAM credentials. While language clients can provide their IAM credentials to the Flare credentials provider, they must manage IAM credentials themselves. This adds code duplication and complexity to each IDE extension.

Furthermore, the agentic bundle for the CodeWhisperer LSP only supports SSO. If language clients want it to consume IAM credentials, they must start a completely separate bundle which includes the IAM implementation of the CodeWhisperer LSP. This prevents clients from seamlessly switching authentication methods at runtime.

Solution

This feature is split into multiple PRs (in order):
Identity LSP:

1. feat(identity): add support for IAM profile management #1845
2. feat(identity): add support for retrieving IAM user credentials #1869
3. feat(identity): add STS credential management #1846
4. feat: add IAM credentials discovery from process, metadata, and env #2004
5. feat: add telemetry to IAM credentials management #2020
6. feat: add shared config file watcher #2021

CodeWhisperer LSP:

1. refactor(amazonq): split CodeWhispererService into multiple files #1974
2. feat(amazonq): add token methods to codewhisperer clients #1958
3. refactor(amazonq): combine IAM and SSO implementations of AmazonQServiceManager #1984
4. refactor(amazonq): change AmazonQServiceManager references #1960

Each PR will be merged into liramon/flare-iam-base, which will be merged into branch main at the end.

These changes allows the identity LSP to load and save IAM credentials to the shared config, generate temporary credentials from STS AssumeRole, and cache/invalidate/refresh temporary credentials. This PR also contains a refactor of the CodeWhisperer LSP to switch between consuming IAM and bearer credentials at runtime.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 79.65116% with 315 lines in your changes missing coverage. Please review.
✅ Project coverage is 61.39%. Comparing base (89ae720) to head (854f6e0).

Files with missing lines	Patch %	Lines
...ed/codeWhispererService/codeWhispererServiceIAM.ts	58.70%	83 Missing ⚠️
server/aws-lsp-identity/src/iam/utils.ts	59.39%	54 Missing ⚠️
...lsp-identity/src/language-server/identityServer.ts	0.00%	44 Missing ⚠️
server/aws-lsp-identity/src/iam/iamProvider.ts	82.06%	39 Missing and 1 partial ⚠️
...erver/aws-lsp-identity/src/sts/stsAutoRefresher.ts	69.04%	26 Missing ⚠️
...s-lsp-identity/src/sts/cache/fileSystemStsCache.ts	88.23%	15 Missing and 1 partial ⚠️
...d/codeWhispererService/codeWhispererServiceBase.ts	94.14%	12 Missing ⚠️
.../codeWhispererService/codeWhispererServiceToken.ts	80.64%	12 Missing ⚠️
...codewhisperer/src/shared/streamingClientService.ts	58.33%	10 Missing ⚠️
...sp-identity/src/language-server/identityService.ts	94.11%	9 Missing ⚠️
... and 3 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1981      +/-   ##
==========================================
+ Coverage   60.99%   61.39%   +0.40%     
==========================================
  Files         239      247       +8     
  Lines       52533    53743    +1210     
  Branches     3174     3271      +97     
==========================================
+ Hits        32041    32998     +957     
- Misses      20431    20682     +251     
- Partials       61       63       +2     

Flag	Coverage Δ
unittests	61.39% <79.65%> (+0.40%)	⬆️

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