Bug 21260: Simple adjustments in Availability blocks

Bug 21260: Simple adjustments in Availability blocks

[1] Add reallynotforloan=0 test to 'Block 1'. Add a period after No items available.
[2] Remove the if with colon block. Remove the <br> and add a span for reallynotforloan (items on order).
[3] Add a 'Not available' label for the reallynotforloan block.
[4] Remove the On order status, since it is not used anymore since 7611.

Test plan:
See subsequent patches.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: ava li <rubyli208@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>