Fix layer tap interrupted

[xs5871]

resolves #739 and adds unit test for that scenario.

[regicidalplutophage]

This only fixes case 1 where we press a non-holdtap key within the tap time of a LayerTap key.
Does not fix case 2 where we press a holdtap within the tap time of modtap: the output is still not layer shifted and both keys produce tap output.

[regicidalplutophage]

The #741 is not what caused the problem in the second case, although not specifying tap_time changed output from tapped key to held key. The expected output is layer shifted key.

[regicidalplutophage]

It doesn't fix layertap completely, but somewhat improves it. I think it can be merged for what it is.

[xs5871]

How about now?

[regicidalplutophage]

Nope, sorry

[xs5871]

Did you set tap_interrupted=False? I tripple checked and all the unit tests and hardware testing show that it's working properly in any combination of scenarios.

[regicidalplutophage]

I'm positive that this PR alone did not fix LayerTap + HoldTap scenario for me with keys being configured as:

TEST2 = KC.HT(KC.F, KC.MO(3), prefer_hold=True, tap_interrupted=True)
TEST3 = KC.HT(KC.F, KC.LSFT, prefer_hold=True, tap_interrupted=True)

In combination with #743 however, it works. #743 also seem to have resolved #741.

[regicidalplutophage]

In combination with #743 resolves issues #739 and #741