Add ifAlreadyRunning/ifNotAlreadyRunning macro condition.

[kareltucek]

Tests whether another macro slot is currently playing the same macro index as the current one. Useful to prevent re-entering a macro that is already in progress.

Changelog:

• feature: add ifAlreadyRunning/ifNotAlreadyRunning conditions for simple re-entrancy guards inside macros

Test: tap twice this macro, expect only one output:

ifNotAlreadyRunning {
    write "Hello!"
    delayUntil 5000
    write "Good bye!"
}

Closes #1534