Teleporter multiple asset support: Add recover mechanism for missing mapping

[wsdt]

related to #959

Issue Type

[ ] bug report
[ x] feature request

Current Behavior

Teleporter service just logs when a tokenAddress is not supported.
Refer to service.ts (Teleporter):

   try {
            const receivingChainTokenAddr = this._getSupportedAssetBySymbol(
              sourceChainTokenAddr,
              sourceChainId.toNumber(),
              chainId,
              this.state.supportedChains
            )

            const [isTokenSupported, , , , ,] =
              await this.state.Teleportation.supportedTokens(
                sourceChainTokenAddr
              )
            if (!isTokenSupported) {
              throw new Error(
                `Token '${sourceChainTokenAddr}' not supported originating from chain '${sourceChainId}' with amount '${amount}'!`
              )
            } else {
              disbursement = [
                ...disbursement,
                {
                  token: receivingChainTokenAddr, // token mapping for correct routing as addresses different on every network
                  amount: amount.toString(),
                  addr: emitter,
                  depositId: depositId.toNumber(),
                  sourceChainId: sourceChainId.toString(),
                },
              ]
              this.logger.info(
                `Found a new deposit - sourceChainId: ${sourceChainId.toString()} - depositId: ${depositId.toNumber()} - amount: ${amount.toString()} - emitter: ${emitter} - token/native: ${sourceChainTokenAddr}`
              )
            }
          } catch (e) {
            this.logger.error(e.message)
            // TODO: Add recovery mechanism
            // TODO: Save somewhere to recover(!) or generally fail (do once db teleporter is merged)
            // TODO: for both when getSupportedAssetBySymbol fails or when onchain support is missing
          }

Desired Behavior

Assets are explictly supported or not supported in the Teleporter contract. The Teleporter service owns the routes between networks and maps token addresses to each other for every network - we may want to save failed disbursements for this kind of configuration mistake and possibly add a recovery mechanism. Same applies to missing on-chain token support to not loose the information and have an inconsistent state for already disbursed assets / to not block other disbursements.

[wsdt]

fixed through #959

Went for a much more simpler approach instead of implementing a full blown recovery mechanism to keep complexity as low as possible.