issueReporter: fix branded-build media and repository tests #343343

Problem

Fixes https://github.com/microsoft/vscode-engineering/issues/4294

The tests assumed the OSS product URL's lowercase owner and WebM playback availability. Branded builds use Microsoft/vscode, and encoder support alone does not establish that recorded video can be played back.

Fix

• Derive product-dependent expectations from the configured destination and retain explicit mixed-case routing/deduplication coverage.


• Require both encoder and decoder support when selecting recording formats, with fallback from an unusable preference.


• Keep real codec tests enabled. Supported formats must decode; unsupported fixtures must explicitly reject. Isolate the missing-duration import test from codec availability.

No tests are disabled. Production repository display casing and media-resource access rules remain unchanged.

Validation

• 
  npm run build-fast -- --client-only: passed.


• 
  npm run typecheck-client: passed.


• Targeted ESLint on all seven changed files and git diff --check: passed.


• The implementation run passed 204 tests across the six affected suites. Independent official Electron runs passed 114 media/import/recording tests and 11 affected form/overlay/capitalization checks, with no failures or skips.

Validation used macOS OSS Electron. The exact Microsoft Electron download was blocked by package-feed ReadPackages access. Branded Windows, macOS, and Linux CI must confirm recovery; this PR does not claim that build 487717 is fixed before that run.