Bug 23229: Only load ILL table JS when needed

Bug 23229: Only load ILL table JS when needed

This patch prevents the JS associated with the ILL table from loading
unless we're actually displaying the table. This has the knock on effect
of not causing the "get all ILL requests" API request to fire when
loading any ILL page.

Test plan:

- Go to "ILL requests" page
- TEST: Observe that the table loads all ILL requests
- Go to the "New ILL request" page for any installed backend
- TEST: Check the browser dev tools "Network" panel, observe that the
/api/v1/illrequests?embed=metadata,patron,capabilities,library,status_alias,comments,requested_partners
request is not made.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>