Job Visibility Enhancement: Submit Job Listing

[Gnodesign]

Changes Proposed in this Pull Request

I've received numerous requests from users for visibility options on the job submission page. Currently, most users manage this through third-party plugins, but since WPJM already offers visibility options for "Browse Jobs" and "View Job," I thought it would be beneficial to add similar options for "Job Submission" as well.

Testing Instructions

• Go to "Job Manager -> Settings -> Job Visibility"
• Add a role to "Submit Job Capability"
• Visit the job submission as a not logged in user

New or Updated Hooks and Templates

• New filter: job_manager_user_can_view_submit_job
• New template: access-denied-submit-job_listing.php

[donnchawp]

Thanks @Gnodesign. This is more complicated than #2910, but we'll take a look at this. Appreciate the work you put in here.