Disable/enable BLE for low power applications

[Rapsssito]

I am currently working on a project with very high energy limitations. I use BLE for sending the WiFi credentials to the device for the first time. However, the BLE service service starts at boot and does not stop (never). In my use case, the BLE server becomes useless once the device has connected to a WiFi network.

For this reason, it would be ideal to be able to turn the BLE service off and on on demand with actions like ble.enable and ble.disable like the existing wifi.enable and wifi.disable. Furthermore, I having a parameter to select if the service should start at boot or not will be ideal for further energy savings if the device has already WiFi credentials.

@wifwucite, thanks a lot for the work. I know that managing an open source project like this can be exhausting. I can help if you provide me some indications. Do you think this feature fits this project? If that is the case, do you plan adding this feature in the near future? If not, I can work on a PR, but I will need some initial guidance on where I should start.