Toolbar v6 - update spacer/spaceItems to gap props

[thatblindgeye]

Is this a new page or a change to an existing one?
Toolbar
Describe the enhancement
Followup to React PR patternfly/patternfly-react#10418
Are there visuals for this enhancement? If applicable, please include examples for each state and for varying widths
Include screenshots or links to Marvel or other mockups.

Any other information?

[evwilkin]

Closed by #4172