Fix isolated parser tests for Bitgesell config

[cedar323]

Summary

• update parser tests to use the existing bitgesell / bitgesellMultiWallet test config keys
• mock the remaining parser RPC responses with nock so parser_test.js can run without a local BGLd/Docker service
• keep the batch headers case aligned with dynamically generated RPC ids

Verification

• $env:NODE_ENV='test'; node node_modules\mocha\bin\mocha --timeout 20000 --recursive --require should test\parser_test.js --reporter spec passes on Windows
• git diff --check reports no patch whitespace errors; Git only warns about local CRLF normalization

Note: this PR is intentionally independent from #11 and only touches test/parser_test.js.

[MyTH-zyxeon]

Maintainer-facing review assist for the #39 bounty queue:

I would treat this as a focused test-fix candidate, not a runtime RPC behavior change. It only touches test/parser_test.js (+33/-7) and moves the parser cases from the stale config.bitcoin / config.bitcoinMultiWallet keys to the Bitgesell test config keys. The added nock mocks also make the parser/header cases self-contained, so this file no longer needs a local BGLd/Docker service just to exercise parser behavior.

Acceptance checks I would ask for before merge:

• Run the exact Windows command from the PR body, plus a POSIX equivalent such as NODE_ENV=test ./node_modules/.bin/mocha --timeout 20000 --recursive --require should test/parser_test.js --reporter spec, so the fix is not only PowerShell-validated.
• Keep the dynamic batch-response id: request.id behavior; that is the important part of the headers batch case because request IDs are generated at runtime.
• Keep this separate from Fix npm test runner on Windows #11 as the author notes, because Fix npm test runner on Windows #11 changes the npm runner while this PR only isolates parser tests.

This looks bounty-relevant under BitgesellOfficial/bitgesell#39 because that issue explicitly includes one test group/file fixed by a single PR, but payout/priority still needs maintainer confirmation.