Describe the feature:
Right now, if a user wants to use a non-default index pattern on TSVB, she should type the name exactly as it is. There is no way for the user to search and choose from the existing ones. This is a bad UX as the user should remember the index pattern which is quite difficult especially if there are many index patterns.

We would like to change this and replace the simple input text with a combobox where the user could either choose from the list of index patterns or type freely the index pattern she wants.