Add EQL as an indicator type

[dcode]

Proposed changes

• Adds EQL as an indicator type in the UI
• Adds Python validator using the EQL Python library, implementing the Elasticsearch language variant

Related issues

• Add Elastic EQL as an Indicator type #2094

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality (Not sure how to build and test an environment 😬 )
• I wrote test cases for the relevant uses case (Didn't see one for the other languages)
• I added/update the relevant documentation (either on github or on notion) (I'll check this out)
• Where necessary I refactored code to improve the overall quality (Are you opposed to sorting indicator types alphabetically?)

Further comments

None

[SamuelHassine]

Thanks a lot for this great PR!

[SamuelHassine]

The conflict is caused by:

183 | parsuricata 0.3.2 depends on lark-parser<0.13.0 and >=0.12.0
184 | eql 0.9.12 depends on lark-parser~=0.11.1

[dcode]

I'll work on bumping up the python dependency from the EQL library

[dcode]

Related: endgameinc/eql#61

[dcode]

This is fixed in the upstream PR, but will probably be early next week before the package is pushed to pypi.

[SamuelHassine]

@dcode What do you think about using git+https on the master branch in the requirements.txt to be able to merge?

[dcode]

it's been shipped endgameinc/eql#62

https://pypi.org/project/eql/0.9.13/