allow the duplicate notications

[ganesh641]

Needed apply_filter to allow_duplicate notification in the "bp_notifications_add_notification" function.

[boonebgorges]

Better: let's use bp_parse_args() in bp_notifications_add_notification(), so that any of the params can be filtered.

[ganesh641]

bp_parse_args() is used to get value as filtered parameter for the template page. How do we used bp_parse_args() in bp_notifications_add_notification() function.

[mercime]

#6459 dupllicate

[ganesh641]

Any batch available?

[pareshradadiya]

wp_parse_args is replaced with bp_parse_args. So now we can use "bp_before_notifications_params_parse_args" or "bp_after_notifications_params_parse_args"

[boonebgorges]

In 9992:

Use bp_parse_args() in bp_notifications_add_notification().

This allows devs to modify default arguments, including the 'allow_duplicate'
check.

Props pareshradadiya, ganesh641.
Fixes #6455.