Threat Groups and Software sorting should disregard capitalization

[isaisabel]

As a user, I expect threat groups and softwares in the multi-select dropdown to be in alphabetical order.

However, currently the sort function for these menus respects capitalization, leading to two groups (menuPass and admin@338) to be sorted to the bottom, since they don't start with capitals like the rest of the groups. The sort function should be changed so that it doesn't respect capital letters.

[isaisabel]

Bugfix implemented in bugs/sort-capitalization and merged into develop.