EstimateGas endpoint - nonce should be automatically set the current nonce for the account

[igorcrevar]

Description

• The DebugTransaction, EstimateGas, and Call endpoints should not depend on the nonce provided by the user. Instead, the nonce should be automatically set to the current value for the account.

• I have left the optional parameter forceNonce in DecodeTxn because, in the future, certain endpoints might rely on the nonce provided by the user.

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Breaking changes

Please complete this section if any breaking changes have been made, otherwise delete it

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

Manual tests

• Start cluster
• Execute from the terminal:

cur_nonce=$(cast nonce --block pending --rpc-url http://127.0.0.1:10002/ 0x85da99c8a7c2c95964c8efd687e95e632fc533d6)
gap_nonce=$((cur_nonce + 1))
cast send --legacy --private-key 0x42b6e34dc21598a807dc19d7784c71b2a7a01f6480dc6f58258f78e539f1a1fa --rpc-url http://127.0.0.1:10002/ --async --nonce $gap_nonce 0x03893a7c7463AE47D46bc7f091665f1893656003

• There should be no error
• Try sending tx with cur_nonce also and then both of those transactions should be included in some block