Various implementation details

[szattila98]

• submit button prevent default works strangely before hydration, it is not disabled and submits the form without the js preventing the default behavior
• bottom scrollbar on login fadeout
• regex password validation rework
• account activation page and endpoint that proxies the activation request to the backend. A link to this should come in the activation email, but that also needs some backend config
• eslint does not work on some TS files
• the 'me' hook should call the sveltekit endpoint, not the server directly
• technical error alert component, in case something goes wrong server side we can show the same message everywhere
• make server email configurable