refactor: reword error msg for reporting transactions failing for requiring full-access keys

[miraclx]

Resolves #4746, hopes to be clearer with the error message when using a non-full-access key for a transaction that either has multiple actions or is not a function-call action.

Before:

"The transaction contains more then one action, but it was signed with an access key which allows transaction to apply only one specific action. To apply more then one actions TX must be signed with a full access key

After:

Invalid access key type. Full-access keys are required for transactions that have multiple or non-function-call actions

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Would've been nice if we could resolve this issue with a message like Cannot send money without a full access key but that would require the error variant to encode a cause. But we can at least ease understanding what went wrong with a better error message that properly describes why this variant would be returned.

[frol]

@bowenwang1996 I feel that #4709 did not land to 1.21.x and now we have a discrepancy in the backward compatibility tests.