More work on the teambuilder

List of changes include:
- Fixed team select dropdown not updating when the last team is removed. Added build a team
- Clicking Find Battle without a team redirects to the Teambuilder

On the teambuilder itself
- Move descriptions. Currently more verbose than desired but its a start.
- Highlight selected move rows. Clicking a selected move in the table removes it from the selected moves
- Added a mega forme dropdown. Currently it only attaches the item. Later we will need to implement a mega forme preview
- EV locking, you can go above 510 max EVs when its locked. Locks can be toggled off, but the setting isn't saved yet.
- Collapse the selected moves list on insert/remove. Only empty inputs are collapsed.
not sure what you mean about the mega stone. what is the use case here? what problem is this trying to solve?