Change project structure & get everything 1.0.0-next.1 ready

[vatro]

• [x] Change project structure -> 295eba0d9c77fff90181eba679cd0a2246b8b984
• [x] (rollup template) Satisfy svelte-check -> https://github.com/vatro/svelthree/tree/1.0.0-next.0.16
• [x] (rollup template) Fix build warnings, errors etc. incl. close / fix #53
• [x] (sveltekit template) Check latest next (should be ok as it is)
• [x] Close #55
• [x] Polish / nail down all animation possibilities.
• [x] Fix / close #62
• [x] Create a separate component generator repo (private)
• [ ] Close #70
• [ ] Refactor test scenes and fix any new bugs if needed and not too time consuming, otherwise create new issues for 1.0.0-next.X

[vatro]

~closed in favor of #57~