Allow conditional props

[picklelo]

We should be able to do something like

pc.button(
    "hello",
    color=pc.cond(State.condition, "red", "green")
)

Currently the only way to achieve this is to do

pc.cond(
    State.condition,
    pc.button(color="red"),
    pc.button(color="green")
)

[picklelo]

@ElijahAhianyo is taking this on