initial notification to try Brave Rewards if user is not opted in

[LaurenWags]

Description

Per discussion with @NejcZdovc - logging a tracking issue for initial notification to try Brave Rewards.

From the spec: "If a user is not opted into Brave Rewards, they will see a red notification notifier on the Brave Rewards icon in the URL bar with a “1” indicating that they should click on it. This in turn brings up the panel in its initial state, which is asking that a user opt in. As soon as the panel has been opened, the notification has been viewed and the “1” in the red circle disappears."

Steps to Reproduce

1. Clean profile or upgrade profile without Brave Payments enabled.
2. There should be a 1 in a red bubble on the BAT logo on the URL bar.
3. Clicking on the logo should show the initial panel.
4. Once the panel is opened the notification is considered viewed and should be removed.

[LaurenWags]

Verified passed on macOS

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta(64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Mac OS X

• Verified steps from description and from test plan in https://github.com/brave/brave-core/pull/764

Verification passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows

• Verified steps from description and from test plan in https://github.com/brave/brave-core/pull/764

Verification passed on 17.10

Brave	0.58.14 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Linux

• Verified steps from description and from test plan in https://github.com/brave/brave-core/pull/764 with slight modification since there was no grants on the server.

[srirambv]

This has a different behaviour on Linux. When a clean profile is launched, it flashes the initial notification on the badge and then its removed. Console logs the error

[14157:14157:1212/143847.708418:ERROR:x11_input_method_context_impl_gtk.cc(144)] Not implemented reached in virtual void libgtkui::X11InputMethodContextImplGtk::SetSurroundingText(const base::string16 &, const gfx::Range &)
[14157:14173:1212/143849.455952:ERROR:rewards_service_impl.cc(141)] Failed to read file: /home/sriram/.config/BraveSoftware/Brave-Browser-Beta/Default/ledger_state

Clicking on the BAT logo then brings up the notification and closing and restarting browser still retains the notification icon Recording here: https://drive.google.com/open?id=1Ydf691x6IAekcUcG0BC5FxHzIYt3Nkav