[UI] Fixes around query "explain" and vector field description

Change-Id: I6dc08318514fdc1bd3ee9599c501401d76f2bd5b
Reviewed-on: https://review.couchbase.org/c/cbft/+/203782
Well-Formed: Build Bot <[email protected]>
Reviewed-by: Abhi Dangeti <[email protected]>
Tested-by: Abhi Dangeti <[email protected]>

Author: abhinavdangeti

ns_server_static/fts/static-bleve-mapping/partials/mapping/type-mapping-tree.html

@@ -185,6 +185,8 @@
                   | include term vectors
                 </span>
                 <span ng-if="field.docvalues">| docvalues</span>
+                <span ng-if="field.dims">| dims: {{field.dims}}</span>
+                <span ng-if="field.similarity">| metric: {{field.similarity}}</span>
               </span>
             </span>
           </span>

ns_server_static/fts/static/query.js

@@ -27,6 +27,7 @@ function PrepQueryRequest(scope) {
 
     if (typeof q == "object") {
         if (('query' in q) && (typeof q['query'] == "object")) {
+            q['explain'] = true;
             qr = q;
         } else {
             qr = {