Added Photoshop support to texture groups

[Wyn-Price]

Texture layers are inferred by name, and only with the root layers/groups. A psd file with a layer called Layer1, and a group called Group1 can be linked to textures with the same name. Any layers inside Group1 will be squashed down into a single texture.

There is also a limitation on the blend mode/effects that can be used in photoshop, so please just keep things vanilla.

Test it out here: https://dumbcode-studio-git-photoshop-groups-dumbcode.vercel.app/

Example:

Also included as subsequent changes in this PR:

• ClickableInput is abstracted into a getFilesFromClick function. The original component is now just a button that calls the function. Used for the Read from photoshop file button.
• Added _unsafe_AddToast to unsafe operations. Unsafe operations are a (bad) way that code can call react functions. For example, adding a toast is a react function, but _unsafe_AddToast can be called statically from anywhere in code.
• Context menus in the project page (previously just DownloadAsButton) has been abstracted to ProjectContextMenu. DownloadAsButton keeps the same functionality, but now calls ProjectContextMenu. ProjectContextMenu is now also used when clicking the photoshop button for texture layers/groups.
• WriteableFile.asReadable: () => ReadableFile | null has been added as a way to convert a writeable file back to a readable file. This is used to read a file from outside it being refreshed - used in the Refresh photoshop button.
• Added SVGCaretDown and SVGChain (both unused lol)

[Brotatsun64]

folders don't work, the individual layers load fine but folders don't load the textures within. On top of this transparency doesn't work. it becomes a darker color than the color its based on making dark outlines instead of proper blending. this only happens on the new layering system and has no effect on just loading the texture as a photoshop document

[NeusFear]

From Brotat's testing:

• Need to trim leading and trailing whitespace
• Need to ignore capitalization