Airnode forwards blockchain provider error messages as is

[bbenligiray]

Refer to https://api3workspace.slack.com/archives/C02AYRX8D89/p1681907159870799

Run yarn && yarn main on https://github.com/bbenligiray/fulfillment-analysis and you will see fail() being called with errorMessages such as call revert exception; VM Exception while processing transaction: reverted with reason string "In... This is because the static test call before the fulfillment errored. There are two problems with this:

• It's difficult to make sense of for the user. Only two characters of the revert string is visible.
• It's not guaranteed that the error message of the blockchain provider will not contain secrets (see Improve on-chain error message for failed API calls #1502 (comment))

I think there are two options:

1. Use a generic errorMessage instead
2. Use a generic errorMesssage, but bubble up the revert string when possible

I did make use of the first two characters of the revert message while debugging, so I'm not 100% on 1. That being said, the revert string is embedded in the API response and the format of that likely depends on the blockchain provider implementation, so I'm not sure if this can be done in a generalized way. If 2 seems not doable, 1 is still the way to go because in most cases two characters won't be enough so we won't be losing too much.

[bbenligiray]

Probably related #1651