hw: swap button 3 and 4, routing

hw: fix schematic related issues

hw: add middle battery voltage (with overvoltage protection) to the power input terminal block (replaced by 3-pin)

hw: remove resistor between STM and ESP enable

hw: fix power button function without battery connected (only in schematic)

hw: fix power circuit capacitors value

hw: fix clearence of SERVO3 and SERVO4 near bulk-caps

hw: apply pinout to the schematic

hw: update pinhead library - update pinhead library in RBCX design and modify the XML in `RBCX{.brp/.sch}` for correct import to KiCad

hwBRD: Replace buttons with SMD ones