Add filter for customizing block arguments

[renatho]

Changes proposed in this Pull Request

• It removes the sensei_take_course_block_type_args filter in favor of the generic sensei_block_type_args.

Notice that this is for backwards compatibility, and after the WP 5.5 we should use the register_block_type_args. See this PR for more details.

Testing instructions

• Create a course.
• Add all Sensei blocks to the course.
• Add the following filter, and make sure all the blocks render as a text "Filtered":

		add_filter( 'sensei_block_type_args', function( $args ) {
			$args[ 'render_callback' ] = function() { return 'Filtered'; };
			return $args;
		} );

New/Updated Hooks

sensei_block_type_args - For WordPress < 5.5, filters block arguments. For WordPress >= 5.5, use register_block_type_args instead.

[jom]

Minor change then it is ready 👍

[jom]

Param variable name needs to be updated.

[renatho]

Oops! Fixed here: cb156c1

[gikaragia]

Updated WCPC to use the new filte here

[donnapep]

Note that this filter is showing up as an action in the hook docs. This is because filters need an @return attribute - 4f98ea0.

[renatho]

Good catch! Fixed here: #3789