Fix gas estimation

[darrenvechain]

Description

using the best block + 1 when estimating

Type of change

Please delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• [x] - Added API unit tests
• [x] - PR is open in the e2e repo, must be merged and then the commit SHA should be updated here

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] New and existing E2E tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules
• [x] I have not added any vulnerable dependencies to my code