pgAdmin 4 commit: Refresh the SQL control, whenever necessary.

Refresh the SQL control, whenever necessary.
Also, remove the CodeMirror object for better clean up process.

When a SQL control/tab is rendered in a hidden element, it does not
render really well. Because - it rely on the height, and width of the
container to count the gutten position, and margin, and other elements.

Hence - whenever the tab, panel becomes visible, we will refresh the
control.

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=085ce50545e06c94087f1979e45673b136726fb5

Modified Files
--------------
.../browser/templates/browser/js/browser.js | 1 +
web/pgadmin/misc/sql/static/js/sql.js | 3 ++
web/pgadmin/static/js/backform.pgadmin.js | 53 ++++++++++++++++------
.../tools/debugger/templates/debugger/js/direct.js | 3 +-
4 files changed, 45 insertions(+), 15 deletions(-)