Feature line flags

[d-beamon]

Added a new function called requestInputModeFlags(consumer, flags). It enables the configuration of the flags and it is a binding for the library function gpiod_line_request_input_flags.
Added a new object called LineFlags that include all the flags GPIOD_LINE_REQUEST_FLAG_xxx defined in gpiod.h.

Example:

chip = new gpiod.Chip('gpiochip4');
buttonLine = chip.getLine(BUTTON);
buttonLine.requestInputModeFlags("gpio-basic", gpiod.LineFlags.GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP);

[sombriks]

Hello @d-beamon , what a nice patch! Thank you!

I am merging your contribution now and work on a proper release in this weekend!

[kccarbone]

@d-beamon thanks for the contribution! Adding native support for input flags helped cut down a bunch of code in my project. However, I think you may have forgotten to commit the typescript definition for LineFlags... You use it in your example but I'm not seeing it in the latest release.