This allows for clearing the duplicate filter cache when required and will also clear it
automatically when starting a scan.
This is useful when unexpectedly disconnected from a device and attempting to reconnect.
Previously the scan filter would not report advertisements from a device if it was multi-connectable
and advertising while connected. The result was long delays until the device would be scanned again.
This resolves it by clearing the filter cache on each scan start/clearResults call
and adding a method to NimBLEScan for manually clearing the cache on demand.
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