Add simple player cam control to admin panel

[timotheeg]

In competition, player do not always "face" the board, like Rens in the picture below:

Or this pic where both Akuma and JakeyWinks are sort of facing away from their boards

Nestrischamps could add simple player display controls to control rendering of the player cam. For example:

• horizontal mirror (swap image horizontally)
• shift right/left
• zoom in/out
• reset

At the moment, nestrischamps always centers the player cam feed onto whatever area is available., and the available area changes based on the number of matches shown. For example:

The 2-matches view view is typically OK as it shows a lot from the input feeds, but the single-match view could allow the admin some controls to fine tune what portion of the player cam feed is displayed.

[timotheeg]

Camera control to:

1. Mirror player cam
2. Restart player cam has been implemented