Fix/arbitrum fees

[r-marques]

Description

Turns out that arbitrum uses an EIP-1559 style transactions but since transactions are processed in a first come first served basis adding a priority tip to the miners makes no sense. In the end reverting back to setting only gasPrice in the transactions (non EIP-1559 style) was what solved the issue.

This was tested on arbitrum-one, here is a comparison of the fees:

metamask $0.24 0.00014701ETH

before sdk fix $3.64 0.00227846ETH
after sdk fix $0.32 0.00019846ETH

Is this PR related with an open issue?

Closes #404

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Follows the code style of this project.
• Tests Cover Changes
• Documentation

Funny gif

[aaitor]

LGTM