[pgAdmin4][Patch]: RM#1277 - Few cosmetic issues with preference dialog

Hi,

Please find the patch for issues fixed:
1. Foreign keys listed twice
The label for Exclusion constraint was set to 'Foreign keys'. fixed it.
2. Trigger function, Unique constraint, Primary key should be in title case
3. if user click outside of Preferences window it disappear (it should not
disappear)
set preference alertify dialog option *closableByDimmer to false.*
4. Columns node settings listed twice
Override the *register_preferences* method in Columns
*CatalogObjectColumnsModule* class
because there are two types of columns node, catalogs columns and tables
columns.
so the settings for table columns should also work for catalog columns.
Thats why we are not showing preference option for catalogs column node.
*Ashesh* fixed this issue.

Please review.

Thanks,
Surinder Kumar