Publisher List loader doesn't appear on panel after creating a wallet on slower devices

[LaurenWags]

Engineering notes:

• Due to the fact that server publisher list doesn't begin downloading before panel shows wallet screen
• Need a hook/observer into when process starts to show the loader when it begins or show the loader after wallet creation by default

Description:

Found while testing #1831

Per discussion with @kylehickinson if you enable rewards while on a site (such as brave.com, not something like a blank new tab page), the panel should indicate, with a spinning circle, that the publisher status is being checked. This isn't happening all the time.

Steps to Reproduce

1. Clean install 1.13 (19.10.30.21)
2. Skip onboarding
3. Visit a verified site (such as brave.com)
4. Tap on BAT logo, enable Rewards
5. brave.com shows as unverified

Actual result:
Spinning circle does not appear, so I clicked on Refresh status in the video below. Spinning circle showed briefly but then went away and there was no visual feedback until I reopened the panel.

https://drive.google.com/open?id=1dg0pV6C3kh_I11fS0kbU6EXC01SyqACV

Expected result:
Should not have been able to tap on Refresh Status.

Reproduces how often: [Easily reproduced, Intermittent Issue]
fairly often

Brave Version:
1.13 (19.10.30.21)

Device details:
iPad 5th Gen iOS12

Website problems only:

• did you check with Brave Shields down? n/a
• did you check in Safari/Firefox (WkWebView-based browsers)? n/a

Additional Information

[NejcZdovc]

closing as this will be fixed by brave/brave-browser#9502