Analyze command - Improvements in error handling and logging

[SkowronskiAndrew]

Modest improvement in Error reporting and Archive handling

Explicitly check if a file is a Unity Archive rather than trying to mount every file just in case it turns out to be an archive.

Unity Archives have a distinctive signature string at the start so we can pre-triage which files are actually Unity Archives.
The expected values were confirmed by studying the Unity parsing code and debugging the load of some files in the editor.

Note: This is only a modest improvement because we still don't have some mechanism to predict if a file is a Unity Serialized File without attempting to load it and then failing. So when analyzing the output of a player build many files will still be reported as errors just because they are not actually containing built content.

Logging Improvements

1. Report number of successful, failed and ignored files at the end.
   Previously it was hard to tell if errors were shown whether anything actually had been analyzed.

2. On error move console back to the start of the line, so that errors are not printed at a random indent.

3. Remove the noisy stack trace when there is an exception thrown during file processing.

Testing done

Running against AssetBundle and a Player build. This includes a very large directory of assetbundles from a customer that hits a lot of errors.

Also testing piping the output into a text file to make sure the logging is decent, e.g.

UnityDataTool analyze .  -o ..\out5.db -p "*.asset" -v  2>&1> ..\out.txt

[Copilot]

Pull Request Overview

This PR improves error handling and logging in the Unity data analysis tool by implementing pre-filtering of Unity Archive files and enhancing progress reporting. The changes make the analysis process more efficient and provide better feedback to users.

• Pre-checks files for Unity Archive signatures before attempting to mount them as archives
• Adds comprehensive logging with success/failure/ignored file counts and verbose mode improvements
• Improves error message formatting by moving console cursor to line start

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[SkowronskiAndrew]

Note- i tried for a while to see if i could support more than one build in analyze, e.g. if you have the output of two runs of an Addressables or AssetBundle build in sub-directories side by side.

A "work in progress" attempt is at 2d116a8 but i don't know if that approach is on the right track.