pgAdmin 4 commit: Update the backform control to support sql-fields.

Update the backform control to support sql-fields.

Following are the enhancements:
1. Added border to control which was missing earlier.
2. Allows user to provide height to sql-field control by specifying extraClasses field in model schema.
3. Defined new classes for sql-field control height in overrides.css
4. Added scrollbar to the control.

Usage:

{
id: 'definition', label:'{{ _("Definition") }}', cell: 'string',
type: 'text', mode: ['create', 'edit'], group: 'Definition',
control: Backform.SqlFieldControl, extraClasses:['custom_height_css_class']
}

Branch
------
master

Details
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http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=03349f4af65e2e4bbf4a24e278b4cc7affd44167
Author: Surinder Kumar <surinder(dot)kumar(at)enterprisedb(dot)com>

Modified Files
--------------
web/pgadmin/static/css/overrides.css | 42 ++++++++++++++++++++++++++++++-
web/pgadmin/static/js/backform.pgadmin.js | 17 ++++++++++++-
2 files changed, 57 insertions(+), 2 deletions(-)