Migrate smart scalar and night mode to support Mantine theming (#42347)

* migrate smart scalar to css modules

* lighten theme color

* adjust margin

* map space 1 to xs

* use c prop instead of color

* use rem unit

* use rem unit

* add y margin

* return null when no children

* comment on text variation

* cleanup unused components and add dark mode todo

* remove todo comment

* support night mode in embedding

* lift dashboard theme to redux

* make theme non-nullable with default

* use component prop instead of title tag

* optional display theme

* restore tooltip state

* add default mock state

* remove theme from embed

* replace handleActions with createReducer