Reset the current page to 1 on tab / sort change

When opening a different tab (for example, from Open
to Closed), we should reset the page to 1 to avoid
showing "No results found" page when there are less
issues in a particular tab.

The same applies to sort since it doesn't make sense
to sort a list but leave you on page 2 (which might be in
the middle of the list).

ee/app/assets/javascripts/integrations/jira/issues_list/components/jira_issues_list_root.vue

@@ -135,12 +135,14 @@ export default {
       });
     },
     onIssuableListClickTab(selectedIssueState) {
+      this.currentPage = 1;
       this.currentState = selectedIssueState;
     },
     onIssuableListPageChange(selectedPage) {
       this.currentPage = selectedPage;
     },
     onIssuableListSort(selectedSort) {
+      this.currentPage = 1;
       this.sortedBy = selectedSort;
     },
     onIssuableListFilter(filters = []) {