ACP-108: EVM Event Importing using Warp

[michaelkaplan13]

Defines a standard smart contract interface and abstract implementation for importing EVM events from any blockchain within Avalanche using Avalanche Warp Messaging.

https://github.com/avalanche-foundation/ACPs/pull/108/files?short_path=1d75ea7#diff-1d75ea75e0627146f57fabb775be7116f4e7aa0e4a7e5ff45242514acad468a7

[michaelkaplan13]

The two possible use cases for this type of event importing that first pop into my mind are:

1. Importing data feeds into Subnets that are published on other chains (i.e. price feeds currently on the C-Chain)
2. Proving that an NFT on another chain was minted/transferred to an address. Could be used to grant special permissions to those account in games, special discounts to those accounts for services, etc.

For anyone developing (or planning to) using Subnets, I'd be curious to hear thoughts on #1 as relates to the question of time delay between event publishing and event importing as outlined here.