Fixes a number of issues to Solr Mixin. (#1360)

Fixes issue with Resource Monitoring Dashboard where '~' was missing in query.
Change custom allValues for solr_collection variable in Cluster Overview Dashboard
which was causing an issue in panels when collection label was not present in metrics.
Change custom allValues for solr_collection variable in Query Performance Dashboard
which was causing issue in panels when collection label was not present in metrics.

Author: StefanKurek

apache-solr-mixin/dashboards/apache-solr-cluster-overview.libsonnet

@@ -1653,7 +1653,7 @@ local getMatcher(cfg) = '%(solrSelector)s, solr_cluster=~"$solr_cluster"' % cfg;
             refresh=2,
             includeAll=true,
             multi=true,
-            allValues='.+',
+            allValues='.*',
             sort=1
           ),
           template.new(

apache-solr-mixin/dashboards/apache-solr-query-performance.libsonnet

@@ -1578,7 +1578,7 @@ local getMatcher(cfg) = '%(solrSelector)s, solr_cluster=~"$solr_cluster", base_u
             refresh=2,
             includeAll=true,
             multi=true,
-            allValues='.+',
+            allValues='.*',
             sort=1
           ),
           template.new(

apache-solr-mixin/dashboards/apache-solr-resource-monitoring.libsonnet

@@ -1059,7 +1059,7 @@ local dispatchesPanel(matcher) = {
   },
 };
 
-local getMatcher(cfg) = '%(solrSelector)s, solr_cluster="$solr_cluster", base_url=~"$base_url"' % cfg;
+local getMatcher(cfg) = '%(solrSelector)s, solr_cluster=~"$solr_cluster", base_url=~"$base_url"' % cfg;
 
 {
   grafanaDashboards+:: {