Add batched and extra params settings for the extension

[ThisCakeIsALie]

This PR adds new settings for features that were recently (or not so recently) added to the CLI:

• Source file encoding control: Provides an overwrite for the encoding Reqs2X uses by default when reading tests and source files (releveant for code with non-English scripts such as Chinese or Korean)
• Extra parameters for model requests: Necessary to regulate thinking models and deal with other provider-specific oddities
• Batched mode: Has existed for a long time, however has not been configurable via the extension so far

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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