Replace Old Button with `design-system-react` Button

[sra405]

Utilise the implementation and theming of the design-system-react Button completed here for the following:

Tasks

• Update Button usages to use new component (ideally all, but depends on complexity and time - see list of buttons below).
• Remove old Button component if replacing all (or rename accordingly). It can then be removed from Storybook too

ACs

• All old Button instances replaced with the design system button

Buttons

The components below use the existing editor-ui button that should be replaced with the design-system button.

• BetaBanner
• DownloadButton
• EditorInput
• ImageUploadButton
• NewComponentButton
• NewInputPanelButton
• LoginButton
• LogoutButton
• Dropdown
• Sidebar
• FilePanel
• AccessDenied
• BetaModal
• DeleteProject
• ErrorModal
• GeneralModal
• LoginToSaveModal
• NewFileModal
• NewProjectModal
• RenameFile
• RenameProjectModal
• ProjectBar
• ProjectName
• ProjectIndex
• ProjectIndexPagination
• ProjectListItem
• RunButton
• StopButton
• Notifications
• ToastCloseButton

[sra405]

@KristinaDudnyk to advise current status

[Drayden237]

@adrian-rpf this still seems to be an issue. Might be worth prioritising as part of the bugs we have.

[Drayden237]

I don't fully understand the priority of this. Should this be deprioritised? @adrian-rpf

[create-issue-branch]

Branch issues/605-Replace_Old_Button_with_design-system-react_Button created!