Show loading state indicator for Bitcoin accounts if there is a restore in progress

[srirambv]

Description

Show loading state indicator for Bitcoin accounts if there is a restore in progress

Steps to Reproduce

1. Restore a wallet with Bitcoin account that has transaction
2. There is no indication that account is being restored

Actual result:

No indication of account restore for BTC accounts

Expected result:

Show loading state indicator for Bitcoin accounts if there is a restore in progress

Reproduces how often:

EAsy

Brave version (brave://version info)

Brave | 1.64.19 Chromium: 121.0.6167.85 (Official Build) nightly (64-bit) -- | -- Revision | df0cc8f OS | Linux

Version/Channel Information:

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

Other Additional Information:

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

Miscellaneous Information:

cc: @supermassive @jamesmudgett @kleantzogu

[supermassive]

Restoring BTC account takes some time( 30+ seconds) and we don't have ui to show that. Maybe we should just implement this for new onboarding which runs discovery before onboarding completes(as a part of onboarding ui)