Fixing issues found

fix editor focus + add title config

Typing in the editor kept losing focus — turned out every keystroke
was dispatching a config-changed event which made HA rebuild the whole
editor DOM. Split the activity listeners into input (updates config
silently while you type) and change (dispatches when you leave the
field).

Also added a title config option since "Electricity cost" hardcoded
isn't great when you have multiple dashboards or just want it in
your own language.