pgAdmin 4 commit: 1) Binary path set to the default location in which w

1) Binary path set to the default location in which we install the binaries.
2) Validate path not working if there is a space in the binary path.
3) Handle the case when the path contains '$DIR'.

refs #5370

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=c86a2b643a5d848fbb08d7b37ad8622ed913bcf1

Modified Files
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web/pgadmin/browser/server_groups/servers/types.py | 100 +++++++++++++++++----
web/pgadmin/misc/__init__.py                       |  11 ++-
web/pgadmin/static/js/backform.pgadmin.js          |   2 +-
web/pgadmin/utils/__init__.py                      |  44 +++++++--
web/pgadmin/utils/preferences.py                   |  12 +++
web/regression/python_test_utils/test_utils.py     |   4 +-
6 files changed, 144 insertions(+), 29 deletions(-)