Added XTR111 voltage-to-current converter/transmitter

Added the XTR111 0-20mA/4-20mA transmitter

S4.4 violation: I don't know why but the Vin name is reported as a power pin. It is a reference voltage input.

Datasheet: https://www.ti.com/lit/ds/symlink/xtr111.pdf

Associated MR: kicad-footprints!2647 (merged)

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