[httpquery] fix: add method to parse headers and key/value data (#92)

[savacano28]

Proposed changes

• Add methods to parse string to list for headers and key/value http queries

Testing Instructions

1. Create an inject type: http-query post key/value
2. Add header: Content-Type: application/x-www-form-urlencoded and format request data: msg=data
3. Execute inject
4. Now, update inject: try header empty and the same request data, execute
5. Now try inject with http-query with post raw, execute
6. Now try inject with http-query with put raw, execute

Related issues

• Closes OpenAEV Http Query Injector #92

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality
• For bug fix -> I implemented a test that covers the bug

Further comments