Let the user delete menstruation tag(s) after deleting all entries

[raae]

Deleting entries is now possible after #195, and that should make it possible to change your menstrual tag.

At a later point it should be allowed to change at any point: #208

[raae]

Decided to just to do #208,
so changing this issue slightly.

[raae]

Let's add a button to the DangerCard that lets you clear the menses tag after deleting all entries.

The button should only be enabled when entries.length === 0.
When clicked it should use the upsertMensesTags([]).
upsertMensesTags needs to be imported from ../settings.

[raae]

The above comment is a little out of date, follow steps below @olavea:

Step 1: Add a section similar to delete entries, but with a button that says "Clear choosen tag(s)"
Step 2: Set disabled to true on button when entries.length > 0
Step 3: Make the button show an alert "Clearing tags" when clicked. (This will later be replaced with proper functionality).
Step 4: Wait until @raae has made a clearMensenTags function to be imported from "../settings"
Step 5: Call clearMensesTag when the button is clicked.