limit name and bio to X characters

[berkes]

As a member
And as an instance Admin
When another member writes an entire bookwork in their bio
Or when another member abuses the bio to store large amounts of data
Then I want this limited
So that everyone knows the length of a bio is limited.

Additional feature could be a neat count-down that shows how many characters are left.
Additional feature could be to make this ENV-var configurable so admins can change this setting.
It should be UTF-8 aware.