Register Destination (M-01)

Why this should be merged

Introduces a new required step for destination contracts to "register" with their token source contracts. Token source contracts will now only allow sending to registered destinations. This provides a guardrail that prevents accidental locking of tokens in the bridge contracts if an arbitrary invalid destination contract is provided. In the multi-hop case, if an invalid destination is provided to the source contract, the tokens are sent to a fallback recipient address provided in the message.

How this works

Adds a new RegisterDestinationMessage that all destination contracts send to their configured source contract in their constructor. This message includes the token multiplier information, as well as the initial reserve imbalance of the destination (only non-zero for NativeTokenDestination instances).

As a result of the source contract now knowing the scaling information and initial reserve imbalance, the TeleporterTokenSource now handles the scaling the tokens amount prior to sending messages to a registered destination, and requires sufficient collateral to be added via a new addCollateral function prior to being able to send any bridge events to that respective destination

How this was tested

Unit tests
E2E Tests

How is this documented

READMEs

	Severity Level	Results
Contracts	Critical High Medium Low Note Total	1 0 0 3 13 17
Dependencies	Critical High Medium Low Note Total	0 0 0 0 0 0

ava-labs / teleporter-token-bridge