Fix limit parameter not passed to requests by HTTP backend

[juhoinkinen]

I noticed that the limit parameter in the project configuration had no effect to the number of the suggestions in the case of the HTTP backend. This is fixed by adding that parameter to the POST request, if it is used.

Also adds a test to verify that the the POST request by the HTTP backend actually contains the intended arguments.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.64%. Comparing base (3b5f7a1) to head (011e602).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #792 +/- ## ======================================= Coverage 99.64% 99.64% ======================================= Files 91 91 Lines 6817 6831 +14 ======================================= + Hits 6793 6807 +14 Misses 24 24 ```

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[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[juhoinkinen]

@CodiumAI-Agent /review

[CodiumAI-Agent]

PR Reviewer Guide 🔍

⏱️ Estimated effort to review [1-5]	2
🧪 Relevant tests	Yes
🔒 Security concerns	No
⚡ Key issues to review	None