[Firebase AI] Add `URLContext` tool #411

Job	Run time
quickstart (macos-15, Xcode_16.4)	3m 45s
spm / spm-package-resolved	1m 12s
pod_lib_lint / pod-lib-lint (macos-15, Xcode_16.4, iOS)	2m 43s
pod_lib_lint / pod-lib-lint (macos-15, Xcode_16.4, watchOS)	2m 34s
pod_lib_lint / pod-lib-lint (macos-15, Xcode_16.4, tvOS)	2m 49s
pod_lib_lint / pod-lib-lint (macos-14, Xcode_16.2, iOS)	6m 43s
pod_lib_lint / pod-lib-lint (macos-15, Xcode_16.4, macOS)	2m 30s
spm / spm (macos-15, Xcode_16.4, tvOS)	4m 38s
spm / spm (macos-14, Xcode_16.2, iOS)	2m 44s
spm / spm (macos-15, Xcode_16.4, catalyst)	3m 2s
spm / spm (macos-15, Xcode_16.4, watchOS)	3m 50s
spm / spm (macos-15, Xcode_16.4, visionOS)	3m 57s
spm / spm (macos-15, Xcode_16.4, iOS)	5m 27s
spm / spm (macos-15, Xcode_16.4, macOS)	3m 41s
testapp-integration (iOS, macos-15)	11m 53s
	1h 1m 28s

Provide feedback