Include field label in "Dropdown Filter" name

Problem/Motivation

All "dropdown filters" provided by the year_views submodule have the same name "Year (Dropdown Filter)". If there is more than one year field, a seemingly duplicate "Year (Dropdown Filter)" appears for each, making it difficult (impossible) to tell which filter acts on which field.

Proposed resolution

Include the field name in each filter title. In year.module, line 41:

'title' => t('Year (Dropdown Filter)'),

Should be something like:

'title' => t('@name (Dropdown Filter)', ['@name' => $field_data['title']]),