Align filter on requirements browser with filters on other browsers (display + category filtering)

[jan-at-rhea]

Prerequisites

• [x] I have written a descriptive pull-request title
• [x] I have verified that there are no overlapping pull-requests open
• [x] I have verified that I am following the COMET-IME code style guidelines
• [x] I have provided test coverage for my change (where applicable)

Description

All changes done in the XAML, so no new tests.

There was a weird issue - when columns were declared before the view, the filter didn't work. This is why view was moved up.

[sonarcloud[bot]]

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[MartinFijneman]

verified with 9.4.0 RC2