Minor improvements for gameplay — Precursors: Armored Angels Steam update #401980

- When an opponent's mech is selected, you can press the right mouse button or the "Esc" or "Backspace" keys to return to our active mech. - You can change the camera mode with the right mouse button when shooting our mech and rotate it around. (we plan to hide the action menu in the future in this mode) - Optimization of the UI horizontal scroll viewer. Works faster, uses less resources. - More different enemy mechs you can encounter in the first missions. It will be even more developed in the future. (Increasing the replayability of the game.)