Add the support of loading data from RDB file

[git-hulk]

Search before asking

• I had searched in the issues and found no similar issues.

Motivation

#1684 supports parsing serialized binary formats from Redis
which is also the key implementation of loading the Redis RDB file.
So after that, I think we can support loading data from the RDB file directly.

Solution

Implement other parts of parsing the RDB file.

Are you willing to submit a PR?

• I'm willing to submit a PR!

[xq2010]

I'm willing to submit a PR and will finish it next month.

[git-hulk]

@xq2010 Assigned, feel free to ask any questions if you need.

[xq2010]

@git-hulk There is a commit in this pr:#1798

[git-hulk]

@git-hulk There is a commit in this pr:#1798

Thanks for your efforts!