Improve metrics page

[tj-mai]

• [x] monthly labels should show year and month yyyy-mm
• [x] show number directly next to label, instead of full spacing between number and label, and turn into paragraph instead of headings
• [x] sub labels should be p tags
• [x] add logins as daily charts (365d)
• [x] add registrations as daily charts (365d)
• [x] show 0 values months and days (for all charts)
• [x] add line chart toggle
• [x] instead of 'logins' use 'active users' (Aktive Nutzer)
• [x] should track active usercount per day (DO NOT OVERWRITE counts on previous days)
• [x] use categoryview , group by date AND userId, having userId not null or -1
• [x] remove LastLogin field in user and db