feature&fix(axis):

(1) feature: Enable uniform bandWidth calculation in numeric axis (e.g., for tooltip shadow); it previously only applicable to category axis, but buggy in numeric axis with bar series. And enable the clip of tooltip shadow.
(2) refactor: Introduce a dedicated workflow phase for series aggregation and data statistics computation on a single axis, allowting the results to be reused across multiple features.
(3) fix: Fix duplicate ticks in TimeScale and customValues, which cause jitter of splitArea.
(4) fix: Fix category showMin/MaxLabel handling when step > 1 and showMin/MaxLabel: false
(5) chore: Tweak bad effects introduced by the previous implementation of SCALE_EXTENT_KIND_MAPPING.
(6) chore: Clean some code.