Twitter metadata needs to be generalized for other media publishers

[jasonrsadler]

Description

twitterMetaData for Brave Rewards needs to be generalized so that it can be used for other media publishers (Reddit, GitHub)

No issue to reproduce as this is a dev concern as follow up to brave/brave-core#2665

[GeetaSarvadnya]

Verification passed on

Brave	0.69.128 Chromium: 77.0.3865.75 (Official Build) (64-bit)
Revision	201e747d032611c5f2785cae06e894cf85be7f8a-refs/branch-heads/3865@{#776}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified the test plan from Reddit inline tips link on post menu will now appear brave-core#2665
• Verified Inline Tip is shown when Reddit box is checked
  
• Verified Inline Tip is NOT shown when Reddit box is unchecked
  
• Verified tipping banner for verified and unverified pubs
  
  

Verification passed on

Brave	0.69.128 Chromium: 77.0.3865.75 (Official Build) (64-bit)
Revision	201e747d032611c5f2785cae06e894cf85be7f8a-refs/branch-heads/3865@{#776}
OS	Ubuntu 18.04 LTS

Verified brave/brave-core#2665 and brave/brave-core#2195

Reddit tip disabled

Reddit tip enabled

Banner

Twitter tipping disabled

Twitter tipping enabled

Banner

Verified passed with

Brave	0.69.130 Chromium: 77.0.3865.90 (Official Build) (64-bit)
Revision	58c425ba843df2918d9d4b409331972646c393dd-refs/branch-heads/3865@{#830}
OS	macOS Version 10.13.6 (Build 17G5019)

• Verified test plan from Reddit inline tips link on post menu will now appear brave-core#2665
• Encountered disabling content level tips for Reddit doesn't remove tip button from in-line menu until page refresh #5551
• Logged follow up issue in line tipping for reddit does not show the post you are trying to tip - follow up to 4907 #6252
• Verified the test plan from Add support for Twitter tips brave-core#2195
• inline tip banner for verified/KYC'd publisher:

* inline tip banner for connected publisher:

* inline tip banner for unverified publisher:

* tweet about a tip: