webcompat reporter not remembering if a website has already been reported

[kjozwiak]

Description

The webcompat reporter under Shields isn't remembering if a particular website has already been reported as per the design mentioned via #4262 (comment). Example:

Shields should remember that the user has previously flagged a site for a webcompat issue. In this case, the Shields DOWN state will not have a "Report a broken site" button and instead persist the thank you message.

Should be displaying the following if a website has already been reported before:

Steps to Reproduce

1. download & install 1.3.91 CR: 79.0.3945.117
2. visit https://brave.com and disable shields
3. click on Report a broken site and select Submit
4. click on Shields again and you'll see the Report a broken site button again

Actual result:

Expected result:

Webcompat reporter should remember if a user has already reported a specific site and shouldn't be displaying Report a broken site.

Reproduces how often:

100% reproducible when using the above STR.

Brave version (brave://version info)

Brave	1.3.91 Chromium: 79.0.3945.117 (Official Build) beta (64-bit)
Revision	04f0a055010adab4484f7497fbfdbf312c307f1d-refs/branch-heads/3945@{#1019}
OS	macOS Version 10.15.2 (Build 19C57)

Version/Channel Information:

• Can you reproduce this issue with the current release? N/A
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the dev channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

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

Miscellaneous Information:

CCing @cezaraugusto @karenkliu @rebron @brave/legacy_qa

[karenkliu]

Please fix this bug. CC @alexwykoff @tomlowenthal