SyncModal refactor

[josh-griffin]

The suggestion

SyncModal should be refactored - tidied styles, adjusted to use ModalContainer and simplified code

Why?

• Modals are slowly being transitioned to be children components of ModalContainer or BottomModalContainer as a consistent design
• There are local styles which aren't even used at all defined, styles with fields which are duplicated, styles with fields which aren't doing anything and use of styles in components which aren't actually defined at all.
• Logic could be tidied
• There are unnecessary components used in the JSX which do nothing

Describe alternatives you've considered

N/A

Additional context

N/A