Refactoring code, improving CI and removing unused dependencies.

[nakrovati]

1. Update: vitepress to v1.1.4. Only update to this version, because updating from v1.2.0 to the current one causes an error “[ERR_MODULE_NOT_FOUND]” on build.
2. Update(CI): actions/checkout to v4.
3. Refactor: components. Basically refactoring CSS, removing unused code, or just shortening code.
4. Refactor: move SVG icon code from HTML markup to individual Vue components.
5. Chore: remove *-lock files from .gitignore. Adding them will speed up installation in CI and installation on the computer.
6. Chore(CI): split the Install and Build step into 2 separate ones for better log readability.
7. Chore(CI): add actions/setup-node with NPM caching of dependencies.
8. Remove: plop - it is not used.
9. Remove: @vkontakte/icons - the dependency weighs 20mb and only one icon is used. I replaced it with a similar one from Phoshpor collection.
10. Remove: unocsss - the unocss classes were only used in one component, and not many of them, so I replaced them with a CSS implementation.
11. Remove: @xobityi/scrollbar-width - replaced by native implementation