Problem: panic when store not exists in historical version

[yihuang]

Solution:

• make a dummy store, so client get empty data instead of panic on nil pointer

Description

Closes: #XXXX

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[mmsqe]

should we upstream to main, and might also need in sdk50?

[yihuang]

should we upstream to main, and might also need in sdk50?

yes, proposed to upstream and get approved.