[WIP] feat: add price oracle module

[leonz789]

Description

This is currently a WIP pr to track the process, The code is undergoing rapid development, with the possibility of frequent and substantial changes.

task list:

• [x] basic framework of the module
• [x] state definition
• [x] aggregation logic
• [x] recache aggregation data from KVStore
• [ ] client cli
• [ ] uint test & integration test

This version has implemented logics and rules that are compatible with v2, so a hard fork might not be needed to upgrade to V2.

Rationale

N/A

Example

N/A

Changes

N/A