pgAdmin 4 commit: Update the UI logo. Artwork by Chethana Kumar. Fixes

Update the UI logo. Artwork by Chethana Kumar. Fixes #4208

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=361f7077fd422d7ef459e254a61e14decbd45d8e
Author: Aditya Toshniwal <aditya.toshniwal@enterprisedb.com>

Modified Files
--------------
docs/en_US/images/file_menu.png                    | Bin 16869 -> 36845 bytes
docs/en_US/images/help_menu.png                    | Bin 24827 -> 40222 bytes
docs/en_US/images/object_menu.png                  | Bin 40854 -> 83951 bytes
docs/en_US/images/tool_menu.png                    | Bin 46256 -> 81157 bytes
docs/en_US/images/toolbar.png                      | Bin 13902 -> 44961 bytes
docs/en_US/images/welcome.png                      | Bin 114222 -> 113993 bytes
docs/en_US/release_notes_4_7.rst                   |   1 +
web/pgadmin/browser/templates/browser/index.html   |   2 --
web/pgadmin/static/favicon.ico                     | Bin 2550 -> 78998 bytes
web/pgadmin/static/scss/_bootstrap.overrides.scss  |   3 ---
web/pgadmin/static/scss/_pgadmin.style.scss        |  22 +++++----------------
.../static/scss/resources/_default.variables.scss  |  10 ++++++++--
12 files changed, 14 insertions(+), 24 deletions(-)