WebTorrent - missing percent sign and improve file size labelling

[leobel96]

Description

Missing percentage and measuring unit for file size in WebTorrent

Test plan / Steps to Reproduce

1. Visit https://webtorrent.io/torrents/sintel.torrent
2. Click Start torrent

Actual result:

Expected result:

Reproduces how often:

Easily

Brave version (brave://version info):

0.59.35 Chromium: 72.0.3626.81 (Build ufficiale) (a 64 bit)

Reproducible on current release:

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

Website problems only:

• Does the issue resolve itself when disabling Brave Shields? No
• Is the issue reproducible on the latest version of Chrome? No

Additional Information

Also it would be good the presence of upload speed

[srirambv]

Verification passed on

Brave	0.69.119 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Linux

Verification passed on

Brave	0.69.119 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Windows 7 Service Pack 1 (Build 7601.24494)

Verification PASSED on macOS 10.14.6 x64 using the following build:

Brave	0.69.121 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Mac OS X