Upgrade deprecated intl-messageformat-parser to v6

[marinrusu1997]

Problem
When installing eslint-plugin-i18n-json with jspm, the following warning is displayed
warn (jspm) Deprecation warning for npm:intl-messageformat-parser@5.5.1: backwards incompatible, please upgrade to 6.0 instead
This causes jspm being stuck for a while with the following message
... Finalizing https://registry.npmjs.org/@formatjs/intl-numberformat/-/intl-numberformat-5.7.1.tgz#sha512-wVkzeqIAxfibB7zekX4xJbHrVfqy6zik2xd4f0zhD4UAn/JfxSin4nFfY35VNr7R0ZtvPqrKBnbddEpyXRF+Zw==

Solution
intl-messageformat-parser should be bumped up to it's latest version, v6. There shouldn't be breaking changes, as looking into CHANGELOG, for v6 there were only bugfixes (see), later one version bumps and another bugfix.

[floscher]

Now the warning message reads:

npm WARN deprecated intl-messageformat-parser@5.5.1: We've written a new parser that's 6x faster and is backwards compatible. Please use @formatjs/icu-messageformat-parser

So this should now be used instead: https://github.com/formatjs/formatjs/tree/main/packages/icu-messageformat-parser