pgAdmin 4 commit: Fixes few UI issue with the backform controls.

Fixes few UI issue with the backform controls.

1. NodeAjaxOtions needs to check 'version_compability' in field, and not
   'ver_in_limit' variable. (Thanks Murtuza for pointing that out.)
2. Override the input control to catch the change properly in it.
3. Updated the UniqueCollectionControl and Variable Control to render
   proper template in the header.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=185ac442fcf3cfd3c3fdaa13d9c6591838a6a846

Modified Files
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.../server_groups/servers/static/js/variable.js    | 50 +++++++++++-----------
web/pgadmin/browser/static/js/node.ui.js           |  2 +-
web/pgadmin/static/js/backform.pgadmin.js          | 12 +++++-
3 files changed, 37 insertions(+), 27 deletions(-)