Pre-Match Controls Updated

Changed:
- Removed Show Playing XI from director controls.
- Next Match now uses a dropdown of created matches from tournament_matches.
- Toss graphic now uses the same created match dropdown.
- Toss winner can be Team A or Team B of selected match.
- Optional Match Time and Venue fields are available for Next Match.

Added APIs:
- api/prematch_match_list.php
- api/prematch_match_get.php

Updated:
- api/prematch_graphics_state.php
- assets/js/prematch_director_controls.js

Next planned phase:
- Replay system.