[azadmin] add fakes support

[gracewilcox]

Part of #23355

[Copilot]

Pull Request Overview

Adds support for fake servers and comprehensive tests for both the RBAC and BackupRestore clients, along with necessary client changes to enable request dispatch via context.

• Introduces fake.Server implementations and tests in rbac/fake and backup/fake packages
• Updates client methods to set runtime.CtxAPINameKey for dispatch in test transports
• Bumps dependencies, tooling (goimports), emitter versions, and adjusts coverage goals

Reviewed Changes

Copilot reviewed 32 out of 32 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
sdk/security/keyvault/azadmin/rbac/fake/server_test.go	New RBAC fake server tests for Create/Get/Delete operations
sdk/security/keyvault/azadmin/rbac/fake/internal.go	Generic tracker and utility functions for fake servers
sdk/security/keyvault/azadmin/rbac/client.go	Client methods updated to use CtxAPINameKey in context for spans
sdk/security/keyvault/azadmin/backup/fake/server.go	New Backup fake server with poller dispatch logic
sdk/security/keyvault/azadmin/backup/fake/internal.go	Shared tracker implementation for backup fake server transport

Comments suppressed due to low confidence (2)

sdk/security/keyvault/azadmin/rbac/fake/server_test.go:20

• [nitpick] The variable name is too generic and conflicts with builtins; consider renaming to testName or roleName for clarity.

name      = "name"

sdk/security/keyvault/azadmin/backup/fake/internal.go:36

• Consider adding unit tests for newTracker, get, add, and remove methods to verify correct tracking behavior and thread safety under concurrent requests.

func newTracker[T any]() *tracker[T] {