Group, filter and search assets

[kof]

As a user I want to be able to group images by some name.

Todo

• Allow adding multiple tags to each asset
• Add a way to select multiple tags and filter by that
• Eventually add a search input as an additional feature

Search input might be not necessary if we have a great way to search using #1696

[kof]

Big fan of tags instead of folders, this lets you essentially have the same but you can have way more flexibility with organizing them, one file can be in 2 categories at the same time, which is useful sometimes.

Even more so tags can be read from the meta data of an image and is compatible between file systems of various OSs and photo programs