brave-browser: Calls to BAT-Native-Ledger are blocked when a reconciliation is in progress

Test plan

See https://github.com/brave/brave-core/pull/1800

Description

When a reconciliation is in progress, calls to bat-native-ledger are blocked and queued

Steps to Reproduce

1. Open Brave, enable Rewards, and fund wallet
2. Visit a verified publisher and have added to auto-contribute list
3. Trigger an auto-contribution reconciliation
4. Visit any site and open rewards panel

Additional: During contribution process, go to Rewards, auto-contribute settings and change some settings. Quit the browser (you may have to ‘Force Quit’/‘End Task’) and open publisher_state. None of the changes will have been recorded.

During contribution, sites won’t add to autocontribute list until after contribution is completed.

Actual result:

Only wallet summary is displayed because calls to get publisher related information are blocked. Leave panel open until reconciliation is complete and panel will work properly.

Expected result:

Publisher information should show in the panel

Steps to Reproduce

1. Open Brave, enable Rewards, and fund wallet
2. Visit a verified publisher and have added to auto-contribute list
3. Trigger an auto-contribution reconciliation
4. Go to Rewards and open backup wallet modal

Actual result:

Backup words do not appear.

Expected result:

Backup words should appear.

Reproduces how often:

easily

Brave version (brave://version info)

Brave	0.59.35 Chromium: 72.0.3626.81 (Official Build) (64-bit)
Revision	ac8b982e05014492d1bd7d317628a4f22a97ffa0-refs/branch-heads/3626@{#796}
OS	Mac OS X

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? yes

Website problems only:

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

Additional Information

cc @NejcZdovc @bridiver @ryanml The STRs above are just a couple examples. It seems any call going into bat-native-ledger during reconciliation is queued up until after reconciliation process (right before voting). Seems to have a lesser impact if a non-autocontribute reconciliation is in progress but still somewhat noticeable.

Possibly related: #3345, #3039