Support fast_reboot count as a rule trigger

[crossan007]

It looks like we have a fast_reboot_count counter which is incremented (after a brownout recovery?)

Currently, the only procees "hooked" to fast_reboots is the factory reset (UpdateQuickPowerCycle / SettingsErase / EspRestart).

It would be neat to be able to create a Rule Trigger (https://tasmota.github.io/docs/Rules/#rule-trigger) based on the number of detected "fast reboots"

A possible use case here would be:

• Tasmota-flashed smart plug installed in a "switched outlet"
• Rapidly toggling the (dumb) switch controlling the outlet would increment the fast_reboot_count variable
• A trigger could be invoked to do X action (ultimately caused by simply toggling the dumb-switch

I had opened this as an "issue" before realizing that a "Discussion" was the right forum for this: #12034