pgAdmin 4 commit: 1) Added support for authentication via the web serve

1) Added support for authentication via the web server (REMOTE_USER). Fixes #6657
2) Fixed OAuth2 integration redirect issue. Fixes #6719

Initial patch for 6657 sent by: Tom Schreiber

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=a726635290a91d26226a0b912806c7767a7db56b
Author: Khushboo Vashi <khushboo.vashi@enterprisedb.com>

Modified Files
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docs/en_US/getting_started.rst                     |   1 +
docs/en_US/release_notes_6_1.rst                   |   2 +
docs/en_US/webserver.rst                           |  44 ++++++++
web/config.py                                      |   9 +-
web/pgAdmin4.wsgi                                  |   2 +
web/pgadmin/__init__.py                            |  17 +--
web/pgadmin/authenticate/webserver.py              | 119 +++++++++++++++++++++
.../browser/tests/test_kerberos_with_mocking.py    |   1 +
web/pgadmin/browser/tests/test_ldap_login.py       |   1 +
.../browser/tests/test_ldap_with_mocking.py        |   1 +
web/pgadmin/browser/tests/test_login.py            |   1 +
.../browser/tests/test_oauth2_with_mocking.py      |   1 +
.../browser/tests/test_webserver_with_mocking.py   |  86 +++++++++++++++
web/pgadmin/utils/constants.py                     |   6 +-
14 files changed, 282 insertions(+), 9 deletions(-)