Bug 14393: Add collection code filter to inventory

Bug 14393: Add collection code filter to inventory

This patch adds the ability to do inventory by collection.

_TEST PLAN_

Before applying:
1) Go to "Tools > Inventory/stocktaking"
2) Note that there is no "Collection code:" option

Optionally:
2b) You can create a Barcode file with a single barcode
2c) Don't select anything from "Select items you want to check" (or filter if you know
how to filter to make it faster... doesn't matter)
2d) Click "Submit" at the bottom of the screen
2e) Note that there is no "Collection code" column in the screen output or CSV output
(ie with/without the "Export to CSV file" box ticked before submitting)

Apply the patch.

After applying:
3) Note that there is a "Collection code" filter on the main inventory screen
4) Create a Barcode file with a single barcode for an item with a collection
and upload it using the "Choose file" button.
5) Select that item's collection code from the "Collection code" filter
6) Click "Submit"
7) Note that the screen output and the CSV output contains a "Collection code" column
(ie with/without the "Export to CSV file" box ticked before submitting)

Signed-off-by: kelly mcelligott <kpmcelligott@gmail.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>