pgAdmin 4 commit: Add support for extensions.

Add support for extensions.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=c950683fa17cc0be132a3e314e5e5b5b7d2c32b8
Author: Surinder Kumar <surinder.kumar@enterprisedb.com>

Modified Files
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.../servers/databases/extensions/__init__.py       | 480 +++++++++++++++++++++
.../extensions/static/img/coll-extension.png       | Bin 0 -> 1017 bytes
.../databases/extensions/static/img/extension.png  | Bin 0 -> 996 bytes
.../templates/extensions/js/extensions.js          | 254 +++++++++++
.../extensions/templates/extensions/sql/create.sql |  19 +
.../extensions/templates/extensions/sql/delete.sql |   8 +
.../templates/extensions/sql/extensions.sql        |  12 +
.../templates/extensions/sql/properties.sql        |  17 +
.../templates/extensions/sql/schemas.sql           |   3 +
.../extensions/templates/extensions/sql/update.sql |  10 +
10 files changed, 803 insertions(+)