wip: feat: Make foam respect the .gitignore file

[TieWay59]

impl #1388

[TieWay59]

I have already fixed some issues with Uri.file and should replace it with something like Uri.joinPath for usage. I am not sure if this is a standard practice. @riccardoferretti

The current effect is that all ignored information is read upon program initialization:

However, if the ignore is updated, it will not refresh due to saving the file.

TODO：

1. Ensure that the semantics of the .gitignore file are correctly represented in glob ignore patterns.
2. Design logic so that updates to the ignore file are dynamically read when the command foam: update wikilink def is executed. I want to consult with @riccardoferretti on whether this is reasonable. What code locations should I refer to?

UPD： The .gitignore file is actually an extension of glob patterns, adding more path rules, comments, and negation features. I can easily parse comments, and negation features, and path rules might differ less from glob patterns.

[riccardoferretti]

Regarding point n.2 you can refer to how we handle changing the related configuration, e.g. foam.files.ignore - see extension.ts:93. Basically, i consider acceptable to ask the user to reload the window to apply the updates