feature: Improve all functions of the store

[sjcsjc123]

id	issue	people	process
1	store method GetRegionByKey
2	store method GetRegionByID
3	store method AddRegion
4	store method RemoveRegion
5	store method Split
6	store method Merge
7	store method GetSize

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[wangchenguang123]

I'm trying hard to do, but I don't know if I can make it

[sjcsjc123]

In these days I will try to implement a method out, you can look at the others first