[Rails] Truncate Story filter select options in new CMS

[rudokemper]

The new Terrastories CMS (accessed at /member/) adds a new filter tool for filtering through Stories.

Currently, the three select boxes for this filter tool for Place and Speaker are populated by the names from records in these two models, and depending on the length of the names, the select boxes can grow quite large, and could result in undesired overflow of the filter tool past the screen width.

Let's truncate the length of the names that are shown in these boxes to 30 characters.

[lauramosher]

The CSS for this uses "max-content" to dictate the width. Clearly that is not ideal.

Let's instead use a fixed width instead or a min-content with min-width. Truncating the actual names could cause confusion or remove useful information when filtering.