Fix MAUI testing with SDK versions earlier than global.json

[Copilot]

Problem

When trying to run MAUI performance tests against an SDK version that is earlier than the one specified in global.json, the installation fails. This happens because:

1. MAUI tests get SDK versions from a remote JSON file (e.g., https://maui.blob.core.windows.net/metadata/sdks/net9.0.json)
2. If this version is earlier than what's in global.json, it gets ignored due to DOTNET_MULTILEVEL_LOOKUP=0 setting
3. This causes failures in the build pipeline when trying to extract base path information

Solution

This PR implements a temporary removal of global.json when installing the MAUI SDK if the version is earlier than the one specified in global.json. This allows the earlier SDK version to be installed without being ignored by the .NET SDK's version resolution logic.

Key aspects of the implementation:

1. Uses semantic versioning for accurate comparison of SDK versions
2. Temporarily moves global.json out of the way when needed
3. Includes robust error handling to ensure global.json is always restored
4. Maintains proper backup mechanisms to prevent data loss

The changes are isolated to the MAUI installation code and won't affect other parts of the codebase.

Fixes #4355.

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