test: stop focusing bridge SDK tests

[1507819106zxzx-crypto]

Summary:

• Remove committed focused Jest tests from the bridge SDK suite so the full intended test inventory is visible again.
• Mock bridge status/balance/contract reads in WBGLBridgeSDK tests so the default suite does not depend on live bridge HTTP responses or local private keys.
• Gate the real BGL/WBGL swap integration tests behind RUN_BRIDGE_INTEGRATION_TESTS=true plus EVM_PRIVATE_KEY and BGL_PRIVATEKEY_OR_SEED, preventing accidental gas-spending/private-key tests in normal CI runs.

Verification:

• npm test -- --runInBand (1 suite passed, 2 integration suites skipped by default; 8 passed, 4 skipped)
• npx tsc -p tsconfig.json --skipLibCheck
• git diff --check

Notes:

• npm install --ignore-scripts currently hits the repo's existing eslint peer dependency conflict; I used --legacy-peer-deps for local verification.
• npm run build:main currently fails before project sources on the latest transitive @types/node declarations with TypeScript 4.9, so I verified with skipLibCheck as a local dependency workaround.
• npm run test:prettier still lists pre-existing non-test source files; the three changed test files are now formatted.

Related bounty: BitgesellOfficial/bitgesell#39
Payout address if accepted: 0x4451dF3D21925eF7a62D20eEdc80B99f7140C5D2