feat(registrar): allow `getApplicationsPage` to return apps for user unbound by vo

Description

feat(registrar): allow getApplicationsPage to return apps for user unbound by vo

• vo parameter for getApplicationsPage is now optional
• when not provided, the method returns all applications for the query user
• new policy which allows this flow only for PERUNADMIN

How to test

Try mainly the FE part of the changes, but you can use RPC calls if u want to be thorough

Author's checklist

• I have followed the contribution guidelines
• This MR has been tested or does not change functionality
• I have added relevant merge request dependencies (if this MR has any)
• I have added the correct labels
• I have assigned reviewers (if any are relevant)
• I have edited the documentation (if the changes require it) or I have noted the need for the change if I do not have access to the documentation
• I have marked all introduced BREAKING CHANGES or necessary DEPLOYMENT NOTES in the commit message(s)

Reviewer's checklist

• This MR has been tested or does not change functionality
• This MR has correct commit message format

Other information

N/A

Related issues

Re STR-1596