Cleanup folder structure

[x] Components should be in parent folder with same name, and all related files in that folder.
[x] Use path aliases, instead of relative paths, something like this in tsconfig:
```
"baseUrl": ".",
"paths": {
  "@/*": ["./*"]
}
```
[x] Use styleguide helper components same as in konto (Wrapper, Stack)
[x] sShowcases can be more condensed, e.g. headings can be in one frame...
[x] Do not use React.FC syntax
[x] Remove word "Type" from types, e.g. SectionGroupPropsType --> SectionGroupProps

bratislava / component-library