ISSUE-5201: Removes splitting of string while setting default course tools.
ISSUE-5201: Updates db while upgradation when splitting of string is removed when setting default course tools.
ISSUE-5201: Run SQL qyery only if home_defaults_2 or main_defaults_2 exists
ISSUE-5201: Adding a new class file mods/_core/modules/classes/ModuleUtility.class.php for extracting and sharing code in mods/_core/courses/admin/default_mods.php and mods/_core/modules/default_mods.php as they share similar code and logic.
ISSUE-5201: Eliminating code duplication by creating a function
ISSUE-5201: Declaring set_config_values() as a static method and passing required inputs as parameters in set_default_tools() function.
ISSUE-5201: Moving exit; out of the method.
ISSUE-5201: Changing SQL queries to use queryDB().
ISSUE-5201: Creating functions to eliminate duplication in mods/_core/modules/classes/ModuleUtility.class.php
ISSUE-5201: Removing unnecessary code for queries that do not return anything.
ISSUE-5201: Using appropriate quotes, i.e, using ' in PHP and " inside of php strings for SQL.
ISSUE-5201: Changing mods/_core/modules/classes/ModuleUtility.class.php to use soft tabs with 4 spaces.
ISSUE-5201: Dehydrating the code by declaring variables that are reused in the queries.
ISSUE-5201: Refactoring code in a loop where same query is executed with different table names.