Implement basic components like flip-flops, (de)multiplexer and encoder/decoder

[SimonBuxx]

These should be implemented in-code, not as custom components.

• [x] RS latch/flip-flop
• [x] Clocked RS flip-flop
• [x] D latch/flip-flop
• [x] Multiplexer (n to 1)
• [x] Demultiplexer (1 to n)
• [x] Half adder
• [x] Full adder
• [x] T flip-flop
• [x] JK flip-flop
• [x] (Priority) Encoder
• [x] Decoder
• [x] (Synchronous) Counter
• [x] Shifting register
• [x] Constant HIGH/LOW

[SimonBuxx]

Master-slave flip-flops handled in issue #61