Uniform implementations
In the nft module, it happens that sometimes we have (as is normal) part of a similar code.
For example, it happens for the GetAllCollections method
https://github.com/bitsongofficial/go-bitsong/blob/84691c819214a1f9b9dd844ea2b49b7ccc8ece1b/x/nft/keeper/collection.go#L42-L55
and the GetAllLastMetadataIds method
https://github.com/bitsongofficial/go-bitsong/blob/84691c819214a1f9b9dd844ea2b49b7ccc8ece1b/x/nft/keeper/metadata.go#L9-L22
Even if they share a big part of the code they present some differences in the implementation. This is a very low-priority issue, but it could be useful to uniform the implementations.
Okay
Similarly, we could refactor a bit for GetLastMetadataId method.
The same could be done between GetAllMetadata WRT GetAllCollections.