Test and merge feature branch

[artem30801]

What changed:

• Data checks in table changes
• Added indication via red\green cell of connected/disconnected copters
• Added funtionality to remove clients via user menu or/and automatically remove disconnected clients (note: ENABLED in config by default)
• Added funtionality to rename copter (including client side) directly from server GUI table (double click on ID to rename). Server will send new id name or command to client and change copter name on client response.

[goldarte]

If client is connected for some long time before sending command and if you try to send command, there will be a huge time gap (about 10 seconds) until the command reaches the client.

[goldarte]

Also, we should change not only client's name, but the hostname too. For this, the client should change 'hostname' paraneters in files: /etc/hostname, /etc/hosts and 'ROS_HOSTNAME' parameter in ~/.bashrc and then execute sudo systemctl restart dhcpcd.

[goldarte]

Now if selfcheck is not OK, it shows nothing.