[WIP] Decreasing the false positive ratio with new pre-filters

[radekk]

Description

This PR is meant to reduce the number of false positives. Multiple improvements include:

• Ignoring non-printable ASCII characters.
• Reducing 35% of words detected in a secret to 30%.
• Ignore a content of ./dist directory.
• Ignore a content of package.json and package-lock.json files.
• Ignore common regular expression patterns.

Therefore:

• Remove legacy symlink to webtask binary.
• Do not call a Slack trigger by default.
• Update NVM version in the Dockerfile.

Testing

• This change adds test coverage for new/changed/fixed functionality

Checklist

• I have added documentation for new/changed functionality in this PR or in auth0.com/docs
• All active GitHub checks for tests, formatting, and security are passing
• The correct base branch is being used, if not master