refactor: snapline and brush-select keep lineWidth after canvas zoom

[Aarebecca]

• The lineWidth of snapline and box of brush-select won't affected by canvas zoom

• Fix trigger brush select, 'Shift' + 'drag' operation won't trigger 'drag'

[Noctsyndrome]

brush select by drag (with no shortcut key) is not working after this patch. example: https://g6-next.antv.antgroup.com/examples/behavior/select#brush