Bug 19481: Set default sort options as sortable in ES default mappings

To test:
1 - Setup Koha with ES
2 - perform a search
3 - try sorting by pubdate, acqdate, popularity, or title
4 - Search fails!
5 - Apply patch
6 - visit:
/cgi-bin/koha/admin/searchengine/elasticsearch/mappings.pl?op=reset&i_know_what_i_am_doing=1
7 - Re-index ES
8 - Perform search
9 - All sorting options should work

Signed-off-by: David Bourgault <david.bourgault@inlibro.com>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

admin/searchengine/elasticsearch/mappings.yaml

@@ -583,17 +583,17 @@ biblios:
       - facet: ''
         marc_field: 952d
         marc_type: marc21
-        sort: ~
+        sort: 1
         suggestible: ''
       - facet: ''
         marc_field: 952d
         marc_type: normarc
-        sort: ~
+        sort: 1
         suggestible: ''
       - facet: ''
         marc_field: '9955'
         marc_type: unimarc
-        sort: ~
+        sort: 1
         suggestible: ''
     type: date
   an:
@@ -1594,12 +1594,12 @@ biblios:
       - facet: ''
         marc_field: 952l
         marc_type: marc21
-        sort: ~
+        sort: 1
         suggestible: ''
       - facet: ''
         marc_field: 952l
         marc_type: normarc
-        sort: ~
+        sort: 1
         suggestible: ''
     type: sum
   itemnumber:
@@ -1916,17 +1916,17 @@ biblios:
       - facet: ''
         marc_field: 008_/7-10
         marc_type: marc21
-        sort: ~
+        sort: 1
         suggestible: ''
       - facet: ''
         marc_field: 008_/7-10
         marc_type: normarc
-        sort: ~
+        sort: 1
         suggestible: ''
       - facet: ''
         marc_field: 100a_/9-12
         marc_type: unimarc
-        sort: ~
+        sort: 1
         suggestible: ''
     type: ''
   publisher:
@@ -2327,7 +2327,7 @@ biblios:
       - facet: ''
         marc_field: 245a
         marc_type: marc21
-        sort: ~
+        sort: 1
         suggestible: '1'
       - facet: ''
         marc_field: '246'
@@ -2407,7 +2407,7 @@ biblios:
       - facet: ''
         marc_field: 245a
         marc_type: normarc
-        sort: ~
+        sort: 1
         suggestible: '1'
       - facet: ''
         marc_field: '246'
@@ -2462,7 +2462,7 @@ biblios:
       - facet: ''
         marc_field: 200a
         marc_type: unimarc
-        sort: ~
+        sort: 1
         suggestible: '1'
       - facet: ''
         marc_field: 200c