Bug 34112: Replace fa.fa-pencil-alt with fa-solid.fa-pencil in edit buttons

Bug 34112: Replace fa.fa-pencil-alt with fa-solid.fa-pencil in edit buttons

The FontAwesome class "fa-pencil-alt" works in v.6 but is actually a v.5
class. We should use "fa-solid fa-pencil" instead.

This patch also corrects some leftover instances of "fa-edit"

To test, apply the patch and view some pages in the OPAC and staff
interface which have updated icons, e.g.

 - Administration -> Libraries
 - Catalog -> Bibliographic details
 - OPAC -> Bibliographic details

Confirm that the pencil icon looks correct. Checking all modified
templates is probably too much, but inspecting the patch should show
that only fa-pencil-alt and fa-edit icons are affected.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>