Add `setItems` support to redis driver

[screeny05]

Describe the feature

The redis driver currently already supports getItems via ioredis.mget, so i think it's only reasonable to also support setItems vie ioredis.mset

Additional information

• Would you be willing to help implement this feature?

[screeny05]

I implemented setItems in redis in my own fork. See here:

https://github.com/screeny05/unstorage-driver-redis/blob/main/src/index.ts#L125-L148