Jp/hotfix optional gas price in rpc transaction type

[jp-imx]

Description

I've made GasPrice optional in the transaction struct in jsonrpc/types.go. The previous implementation made it impossible to call eth_getTransactionByHash for EIP-1559 transactions or eth_getBlockByNumber with the transaction details flag. on, if the block contained EIP-1559 transactions.

Changes include

Marking this as a HOTFIX as Immutable needs this issue solved before we can release our public testnet.

• 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

N/A

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

I had a local polygon-edge chain with 4 nodes. Three of them running v1.0.0. One of them running a version with this fix. A call to eth_getBlockByNumber with the transaction details flag on would fail on v1.0.0 with nil dereference error, but it would work on the node with the fix.

Documentation update

N/A

Additional comments

N/A

[jp-imx]

@goran-ethernal thanks for approving. I understand there's some flakyness in the CI, so was wondering if you think the failed PolyBFT E2E task action is unrelated to my changes. Note, I don't have access to retrying the action or merging this PR.

[goran-ethernal]

@jp-imx Nope, your changes didn't affect that test. We have fixed that test in: #1702, so we are good to merge this one. Just need one more approval.

[jp-imx]

@goran-ethernal do you need me to merge that PR or maybe develop into my branch? Or can we merge as is? I can't retry the build though 🤔

[goran-ethernal]

@jp-imx No need, this test has nothing to do with your changes, so we can merge this PR. I left a small comment. After that, we can merge it.