Bug 24866: (follow-up) Replaced tabulations by dashes

Bug 24866: (follow-up) Replaced tabulations by dashes

The rendering of SELECT elements is up to the browser.
But Bug 16123 CSS code 'style="padding-left: xx' doesn't work on modern browsers.

Based on the previous contribution, this fix replaces CSS style attribute with dashes, creating a leveled structure that should work with most browsers.

Tested on Linux Ubuntu with Firefox 94.0, Chromium 95.0.4 and Opera 81.0.1
TEST PLAN :

1. Go to the Administration module
2. Add a new budget (ie : Budget 2022)
3. Add a fund to this budget (ie : Book)
4. Add a sub-fund to fund Book (ie : Fiction)
5. Add another sub-fund, this time to sub-fund Book (ie : Adult fiction)
You will have this hierarchy :

Budget 2022
 |____ Book
         |_____ Fiction
                |_____ Adult fiction

6. Go to the Acquisition module
7. Select a vendor and create a new basket
8. Place an order
9. Check the budget dropdown menu

BEFORE PATCH
Book
Fiction
Adult fiction

OR

Book
   Fiction
         Adult fiction

AFTER PATCH
Book
 -- Fiction
 -- -- Adult fiction

 Co-authored-by: Didier Gautheron <didier.gautheron@biblibre.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>