fix: change buttons in wiki modal to anchor tags

[arjunsinghy96]

The action buttons in wiki modal have href attribute
but does not have an event listener for click.
This PR changes the buttons to anchor tags so that they
work as expected when clicked.

Related Tickets

• BB-4360

Reproducing the buggy behavior

1. Enroll in any Course
2. Go to Wiki
3. Create an article
4. Make 2-3 edits and save after each edit
5. Click on Changes
6. Select any revision and click "Merge selected with current"
7. Click "Create new merged version". Check that this does not trigger any action.

Testing Instructions

1. Checkout to this branch.
2. Go to Wiki
3. Create an article
4. Make 2-3 edits and save after each edit
5. Click on Changes
6. Select any revision and click "Merge selected with current"
7. Click "Create new merged version".
8. Verify that this triggers a merge request.
9. Wait for request to succeed and page to reload.
10. A new merged revision should be created.

Author Notes:

1. Merge versions action was pretty slow on my local devstack. Please wait for some time for the merge version request to succeed.

[shimulch]

@arjunsinghy96. Thanks for fixing this. LGTM 👍

• I tested this in my local devstack. Reproduced the issue and verified that this PR fixes the issue.
• I read through the code
• [N/A] I checked for accessibility issues
• [N/A] Includes documentation
• [N/A] I made sure any change in configuration variables is reflected in the corresponding client's configuration-secure repository.