feat(ui-mode): reenables the update-snapshots option and uses a dropdown

[Adam Gastineau (agg23)]

Resolves #37007.

Enables UI Mode users to select an --update-snapshots option.

This basic functionality was implemented in #31841, but we put it behind a compile time flag in #31952. I am unsure as to the reasons why.

This does have the side effect of marking a test as passing, but a step as failing, when it updates an existing snapshot. I am unsure if we consider this worth fixing. If so, I suggest we do it in a future change. It still logs that there was a new snapshot written to the console, just like in a terminal reporter.

[github-actions]

Test results for "tests 1"

10 flaky

⚠️ [chromium-library] › library/page-clock.frozen.spec.ts:19 › clock should be frozen `@chromium-ubuntu-22.04-node18`
⚠️ [chromium-library] › library/page-clock.frozen.spec.ts:19 › clock should be frozen `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/page-clock.frozen.spec.ts:19 › clock should be frozen `@chromium-ubuntu-22.04-node22`
⚠️ [chromium-library] › library/page-close.spec.ts:22 › should close page with active dialog `@chromium-ubuntu-22.04-node24`
⚠️ [firefox-library] › library/inspector/cli-codegen-1.spec.ts:1079 › cli codegen › should not throw csp directive violation errors `@firefox-ubuntu-22.04-node18`
⚠️ [firefox-library] › library/inspector/recorder-api.spec.ts:49 › should click `@firefox-ubuntu-22.04-node18`
⚠️ [firefox-page] › page/page-wait-for-function.spec.ts:104 › should work with strict CSP policy `@firefox-ubuntu-22.04-node18`
⚠️ [installation tests] › playwright-cli-install-should-work.spec.ts:25 › install command should work `@package-installations-windows-latest`
⚠️ [chromium-library] › library/inspector/cli-codegen-pick-locator.spec.ts:23 › should inspect locator `@ubuntu-22.04-chromium-tip-of-tree`
⚠️ [webkit-library] › library/inspector/cli-codegen-2.spec.ts:24 › cli codegen › should contain open page `@webkit-ubuntu-22.04-node18`

46615 passed, 802 skipped

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Merge workflow run.