add JSON test case import functionality for CPH extension

[SakuraiQManaka]

feat: add JSON test case import functionality for CPH extension

Description

This PR adds a new feature to import test cases from JSON files in the CPH (Competitive Programming Helper) extension for VS Code. The implementation follows a specific JSON format that supports multiple test cases with multi-line input/output.

JSON Format Specification

The JSON file must be an array of test case objects, where each object contains:

• "in": Array of strings representing input lines
• "out": Array of strings representing expected output lines

Example Format

[
    {
        "in": ["4", "a 64 46", "275 125", "c 11 99", "b 46 64"],
        "out": ["64+46=110", "9", "275+125=400", "11", "11*99=1089", "10", "46-64=-18", "9"]
    },
    {
        "in": ["2", "1 2", "3 4"],
        "out": ["3", "7"]
    }
]

[agrawal-d]

Can you share a screenshot of the UI?
In addition to that, can you share a video of the flow?

Thanks

[SakuraiQManaka]

Sorry for long time no reply, I will recode a video tomorrow, wish not too late.

[SakuraiQManaka]

Can you share a screenshot of the UI? In addition to that, can you share a video of the flow?

Thanks

cph.mp4