[Feature request]: Add buffer length checks

[stijnb1234]

Background and motivation

I've had the situation that I got weird errors because I tried to write text longer than the buffer can hold. There is no check for buffer length < write length.

Describe the solution expected

Add a check if CONFIG_NEX_UART_TRANS_COMMAND_FORMAT_BUFFER_SIZE is smaller then the amount of bytes to write, then return specific error.

Additional info

No response