fix: summary string transformations format (#7221) (#7313)

* fix: summary string transformations format (#7221)

* fix: broken tests fix

* refactor: summary string transformations code to pattern

---------

Co-authored-by: Anze Demsar <anze.demsar@p-m.si>

Author: hip3r

packages/decap-cms-lib-widgets/src/stringTemplate.ts

@@ -36,8 +36,8 @@ const filters = [
 ];
 
 const FIELD_PREFIX = 'fields.';
-const templateContentPattern = '([^}{|]+)';
-const filterPattern = '( \\| ([^}{]+))?';
+const templateContentPattern = ' *([^}{| ]+)';
+const filterPattern = '( \\| ([^}{]+?))? *';
 const templateVariablePattern = `{{${templateContentPattern}${filterPattern}}}`;
 
 // prepends a Zero if the date has only 1 digit