Display an error when fees a for pending transaction cannot be estimated

[josheleonard]

Description

We currently do not display anything when transaction fees fail to load. We should warn the user when this happens

Steps to Reproduce

1. Initiate a solana transaction via a Dapp (https://publishers.basicattentiontoken.org/c/juKB9bpi3m)
2. review the pending transaction

Actual result:

An error is not shown when the fee estimates fail to load

Expected result:

An error should be shown if the fee estimates fail to load

Reproduces how often:

Intermittent issue

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

[kjozwiak]

The above requires 1.62.148 or higher for 1.62.x verification 👍

[srirambv]

Verification passed on

Brave	1.62.149 Chromium: 121.0.6167.75 (Official Build) (64-bit)
Revision	ff84587bd70af9fcbcbe59fc5194ca65082759c4
OS	Windows 11 Version 23H2 (Build 22631.3007)

• Verified steps from issue description
• Verified error message is shown when fee estimates fail

35413.mp4