Adding advanced template filtering

[Mzack9999]

Proposed changes

This PR adds support for advanced template filtering. Available fields are the following standard ones + all those from info metadata section:

id string
name string
description string
tags slice of strings
authors slice of strings
severity string

All fields can be combined with logical operators (|| and &&) and used with DSL helper functions. As an initial prototype implementation

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Examples

nuclei -tc "contains(id,'xss') || contains(tags,'xss')"
nuclei -tc "contains(tags,'cve') && contains(tags,'ssrf')"
nuclei -tc "contains(name, 'Local File Inclusion')"

[forgedhallpass]

I know this is WIP, but still I'd like to mention that this will require extensive testing (multiple positive and negative scenarios) through both unit and integration tests.

[ehsandeep]

• We can add the available options in the nuclei-docs for the same. (Adding tag condition docs nuclei-docs#55)
• Merge conflict