making "consumer" more usable.

[shaarang]

I have an idea to make "consumer" string more usable, so that any program that uses libgpiod can get gpiod_line_request* using the consumer string, this can make easier for the program to query gpiod_line_request* and can be used in this way:

num gpiod_line_value value = gpiod_line_request_get_value(gpio_line_request_from_consumer("LED"), 0);

[brgl]

I'm not following. Please provide a more comprehensive example or - even better - a patch.