Extract additional properties from alerts

[EvanMulawski]

Store VTEC, SAMEEventCode, and NWSEventCode. This provides more information to enhance and simplify automations.

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For example, to handle the initial issuance of a Tornado Warning, instead of using 'Tornado Warning' in Event (or 'tornado warning' in (Event | lower) if you are paranoid about case-sensitive string comparisons like I am) and checking Type == 'Alert' to exclude updates, the SAMEEventCode field can be used:

SAMEEventCode == 'TOR'

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The VTEC field provides even more information when parsed which can also be useful for automations, especially the action group.