SCP-2985: Contract errors are now logged when running the PAB.

[koslambrou]

Errors include uses of throwError inside a Contract and when decoding endpoint parameters.

Here are a few examples.

When a throwError is called in the Contract Monad:

[pab:Info:183] [2022-02-04 00:12:31.10 UTC] Initialising contract PayToWallet with ID 5822163d-4ed9-4b1d-84ba-742855fb4baa
[pab:Info:183] [2022-02-04 00:12:31.11 UTC] Activated instance 5822163d-4ed9-4b1d-84ba-742855fb4baa on W872cb83
[pab:Info:185] [2022-02-04 00:12:31.14 UTC] 5822163d-4ed9-4b1d-84ba-742855fb4baa: "Calling PayToWallet endpoint"
[pab:Error:185] [2022-02-04 00:12:31.14 UTC] 5822163d-4ed9-4b1d-84ba-742855fb4baa: {
    "contents": "THIS IS AN ERROR",
    "tag": "OtherError"
}

When the endpoint parameters could not be decoded (wrong JSON format):

[pab:Info:158] [2022-02-04 00:15:14.83 UTC] Initialising contract PayToWallet with ID 11d859ab-e0ca-40a3-ae68-db3d14320e31
[pab:Info:158] [2022-02-04 00:15:14.84 UTC] Activated instance 11d859ab-e0ca-40a3-ae68-db3d14320e31 on W872cb83
[pab:Error:160] [2022-02-04 00:15:14.87 UTC] 11d859ab-e0ca-40a3-ae68-db3d14320e31: {
    "contents": "Error in $.amount.getValue[0][1][0][0]: key \"unTokenName\" not found",
    "tag": "OtherError"
}

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[raduom]

LGTM