feat: compute backend weight from serviceExport annotation

[ryanzhang-oss]

What type of PR is this?
/kind feature

What this PR does / why we need it:
Compute ATM backend weight from the serviceExport annotation

Which issue(s) this PR fixes:

Fixes #

Requirements:

• run make reviewable for basic local test
• Read and followed fleet-networking's Code of conduct.
• uses conventional commit messages
• includes documentation
• adds unit tests

How has this code been tested

Special notes for your reviewer

[Copilot]

Copilot reviewed 5 out of 8 changed files in this pull request and generated no comments.

Files not reviewed (3)

• config/crd/bases/networking.fleet.azure.com_trafficmanagerprofiles.yaml: Evaluated as low risk
• pkg/controllers/hub/trafficmanagerbackend/controller.go: Evaluated as low risk
• pkg/controllers/member/serviceexport/controller.go: Evaluated as low risk

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 18 lines in your changes missing coverage. Please review.

Project coverage is 80.03%. Comparing base (230bcc6) to head (98f43d2).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/common/condition/condition.go	0.00%	11 Missing ⚠️
pkg/controllers/member/serviceexport/controller.go	94.02%	1 Missing and 3 partials ⚠️
...ontrollers/hub/trafficmanagerbackend/controller.go	92.85%	2 Missing ⚠️
...ontrollers/hub/trafficmanagerprofile/controller.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #253      +/-   ##
==========================================
+ Coverage   79.80%   80.03%   +0.22%     
==========================================
  Files          28       28              
  Lines        3863     3926      +63     
==========================================
+ Hits         3083     3142      +59     
- Misses        623      628       +5     
+ Partials      157      156       -1     

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[Copilot]

Copilot reviewed 6 out of 9 changed files in this pull request and generated no comments.

Files not reviewed (3)

• go.mod: Language not supported
• pkg/controllers/hub/trafficmanagerprofile/controller.go: Evaluated as low risk
• pkg/controllers/member/serviceexport/controller.go: Evaluated as low risk

Comments suppressed due to low confidence (1)

pkg/controllers/hub/trafficmanagerbackend/controller.go:437

• [nitpick] The struct name 'desiredEndpoint' is ambiguous. It should be renamed to 'DesiredEndpoint'.

type desiredEndpoint struct {

[Copilot]

Copilot reviewed 6 out of 10 changed files in this pull request and generated no comments.

Files not reviewed (4)

• go.mod: Language not supported
• pkg/controllers/member/serviceexport/suite_test.go: Evaluated as low risk
• pkg/controllers/member/serviceexport/controller.go: Evaluated as low risk
• pkg/controllers/hub/trafficmanagerprofile/controller.go: Evaluated as low risk

[zhiying-lin]

the minor comments will be addressed in a separate PR, merged the code first to unblock the progress