chore(filters): Introduce filtered search token segment component

Related issue: #590 (closed)

This MR introduces GlFilteredSearchTokenSegment component.

This component provides the same functionality as GlFilteredSearchControlMixin but in a component way. Also, it contains additional functionality, which could be reused across filters components.

The component has two modes of functioning:

• when options prop is not provided it's up to the component owner to render suggestions, using #suggestions slot
• when options prop is provided token segment renders suggestions itself. Additionally, its behavior is changed to "select-like" - if an invalid value is typed and the component is deactivated - it will reset to the previous value