feat: add delay in between multiaction children

[KeryaneK]

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This PR introduces delays in multiaction. They're set to 0 by default to not break current user settings.
Also there are in-built delays - 100ms on keydown and 100ms on keyup. I haven't touched them as I'm not sure about their purpose. Delay settings are saved as an array in multiaction settings.

[CLAassistant]

All committers have signed the CLA.

[KeryaneK]

I've updated it to use parent's action settings to not interfere with plugins.

[KeryaneK]

Basic manual tests done:

• settings do not override themselfs on update and reversion.
• delay action shows only when it's needed ( >2 actions, not after the last, not before the first)
• gaps are proper, even with delay actions in between them

Changing it to "Open" then although any improvement ideas are still welcome.

[KeryaneK]

Force-push was about commit signing - no changes.