Updated gas estimation for gchain

[alfetopito]

Summary

Closes #2389

Gas estimation for gchain now uses proper values

To Test

1. Try to use 100% of xDAI investment and not have enough to claim. Not easy!
2. I managed to do so with these 2 accounts: The account to claim on gchain 0xcbeAd39cC0b43d14c2f240c25f3D5234bbDFF10c and the account to claim with 0x2F144ff590C94871f118583E61fdDd06b98120e4 (PK in on the spreadsheet)

• You should see the low xDAI warning

[github-actions]

• 🔭 GP Swap: CoW Protocol v2 Swap UI

[elena-zh]

Hey @alfetopito , changes LGTM!
As a nitpick I can say that sometimes gas estimation might be a bit optimistic and a user will not wee the warning message, however, will not be able to sign the TX due to insuff. funds error, but the issue is reproducible to every network.

[anxolin]

Maybe increase the numbers a bit just in case? (if elena managed to get the error in MM)

Also, hardcoded doesn't sound too good. Maybe u can consider what I suggested below

[github-actions]

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[alfetopito]

@elena-zh and @anxolin I've bumped the gas estimation 20% over the estimated amount

Also fetching it from Blockscout's gas endpoint

[elena-zh]

Seems that I can't retest it as investment options are no longer available (2 weeks have passed).

[nenadV91]

Merging this to cherry-pick into hotfix branch, should be reviewed after!