Toolbar - updates spacers to gaps

[thatblindgeye]

Follow up to breaking change PR patternfly/patternfly-react#10418

• ToolbarGroup, ToolbarItem, and ToolbarToggleGroup: removed spacer prop. We could provide a fix that will replace the prop with the gap prop and also update the values passed in (e.g. spacerNone => gapNone, or we could just state that we recommend using our gap, columnGap or rowGap props instead.
• ToolbarGroup and ToolbarToggleGroup: removed the spaceItems prop. Will probably require just an error message stating we recommend using marginInlineStart and marginInlineEnd props on applicable components instead.

[Description of the breaking change the rules needing to be created]

Required actions:

1. Build codemod
2. Build test
3. Update readme with description & example