🚀 Addons enhancement & file association

[ItsTheSky]

Overview

Addon enhancement

Each addon can now provide MenuItems (implementing a method in IAddon) to be added in the Addons tab of SkEditor. This will make addon's implementations much easier, and not rely on SkEditor's tabs order. They can also register FileAssociation, which is explained just below :)

File association

When opening a file, SkEditor will now check the registered FileAssociation to open the desired file correctly. Multiple associations can be available for the same extension (e.g. coming from an Addon), and for now SkEditor will just try each of them and use the first "correct" one.

Various modifications

• Added way to enable/disable the footer (bottom bar) as we wish, as to disable it with file types such as images
• Registered a simple Image viewer as the default available association. More will come in this PR!

Tasks

• File association core features
• Addon's tabs registering
• Addons can register their File association
• Provide a prompt to let the user choose and configure the desired file association
• File Type: Image (png, jpg, webp, bmp, ico, svg, tiff)

[NotroDev]

It seems that images can't be opened from a directory that contains special characters, for example Polish Zdjęcia.
You probably need to use Uri.UnescapeDataString(string) in some place

[ItsTheSky]

The new commit adds a warning for binaries file (or any files that are not meant to be openable via a text editor, e.g. containing non-UTF8 chars) with localization.

I added that mainly for projects (thus I hope this PR will be merge soon) as we can open a lot of files directly into SkEditor now.