Provide a Brave Talk tooltip for togetherPageTitle on the new-tab page

[stephendonner]

Description

Provide a Brave Talk tooltip for togetherPageTitle on the new-tab page

Steps to Reproduce

1. new profile
2. launch Brave nightly
3. open a new-tab page
4. on the bottom, hover over the video-camera icon
5. look at the resulting tooltip

Actual result:

This also shows up as an error in the console:

[33320:259:0607/113806.078262:ERROR:CONSOLE(219)] "Unexpected condition on chrome://newtab/: Could not find value for togetherPageTitle", source: chrome://resources/js/load_time_data.js (219)

Expected result:

Should (now) say Call with Brave Talk or something similar, since we've renamed from Brave Together

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.27.48 Chromium: 91.0.4472.88 (Official Build) nightly (x86_64)
Revision	109e9cd038b94a631aea7d40ee3d56c1278f2597-refs/branch-heads/4472@{#1385}
OS	macOS Version 11.4 (Build 20F71)

/cc @petemill @mrose17 @mattmcalister @karenkliu

[srirambv]

Reported internally here https://bravesoftware.slack.com/archives/C7VLGSR55/p1620313398145100

[stephendonner]

This is a duplicate of @GeetaSarvadnya's bug - sorry for not finding it earlier!

#13513