Add hostname support for client mode

[subworx]

Add Hostname setting for client mode.
When the server connects to an existing WiFi, it receives a DHCP IP address which I have to look up in the router, or remember half the MAC address for ARDUINO-xxxxxxxx.

With this change, a specific hostname can be set (default: PS4-WEB) so the host can easily be reached at http://ps4-web after it connected to the existing home network. The ESP Information page now shows information about the connected home network (SSID, ESP IP, hostname).

Also unified line breaks on functions (some void someThing() { and some void someThing()\newline{), and Atom corrected surplus spaces on line endings.

Can also easily add this to PS4-Server-900, ESP32 after my boards arrive (~two weeks)

[subworx]

Not sure if firmware version should be increased for this.
Adding the feature to the description (README.md) would be more fitting for the main project (PS4-Server-900) as the u-variant "only" holds builds but not general information.