dApp: Handle Relayer's errors

[nkuba]

When a POST request is sent to the Relayer it may return an error in the response:

acre/dapp/src/web3/relayer-depositor-proxy.ts

Lines 75 to 87 in ec17423

	// TODO: Catch and handle errors + sentry.
	const response = await axios.post<{ result: string }>(
	this.#defenderWebhookUrl,
	{
	fundingTx,
	reveal,
	staker: `0x${staker.identifierHex}`,
	referral,
	},
	)
	// Defender returns result as string so we need to parse it.
	const { txHash } = JSON.parse(response.data.result) as { txHash: string }

We need to handle such situations, by introducing backoff retries, ensuring the error is logged in the logs and notification is sent to Sentry.

[r-czajkowski]

I think we can close this issue since we use the tBTC API instead of Open Zeppelin Defender.