Fix `custom-forms` heights and position (#25602)
Fix `custom-forms` heights and position (#25602)

Now `.custom-control` will have height equal to `$font-size-base`
Fix custom checkbox and radio top position (we can't subtract rem from unit)
`$line-height-base - $custom-control-indicator-size` is not valid
Because `$line-height-base` is a unitless variable and `$custom-control-indicator-size`
is a unit (rem) variable
bootstrapbrasil/bootstrap,tjkohli/bootstrap,tjkohli/bootstrap,GerHobbelt/bootstrap,twbs/bootstrap,nice-fungal/bootstrap,inway/bootstrap,bardiharborow/bootstrap,Hemphill/bootstrap-docs,yuyokk/bootstrap,kvlsrg/bootstrap,gijsbotje/bootstrap,fschumann1211/bootstrap,bardiharborow/bootstrap,twbs/bootstrap,inway/bootstrap,peterblazejewicz/bootstrap,yuyokk/bootstrap,Hemphill/bootstrap-docs,tagliala/bootstrap,gijsbotje/bootstrap,gijsbotje/bootstrap,inway/bootstrap,Hemphill/bootstrap-docs,fschumann1211/bootstrap,bootstrapbrasil/bootstrap,m5o/bootstrap,zalog/bootstrap,peterblazejewicz/bootstrap,yuyokk/bootstrap,peterblazejewicz/bootstrap,bootstrapbrasil/bootstrap,zalog/bootstrap,coliff/bootstrap,fschumann1211/bootstrap,kvlsrg/bootstrap,zalog/bootstrap,nice-fungal/bootstrap,bardiharborow/bootstrap,GerHobbelt/bootstrap,bardiharborow/bootstrap,coliff/bootstrap,yuyokk/bootstrap,kvlsrg/bootstrap,nice-fungal/bootstrap,stanwmusic/bootstrap,stanwmusic/bootstrap,gijsbotje/bootstrap,stanwmusic/bootstrap,Hemphill/bootstrap-docs,fschumann1211/bootstrap,m5o/bootstrap,tagliala/bootstrap,tagliala/bootstrap,stanwmusic/bootstrap,GerHobbelt/bootstrap