feat!: support returning multiproof

[jawid-h]

Issue being fixed or feature implemented

Support returning multiple store tree proofs

What was done?

• introduce StoreTreeProof message

How Has This Been Tested?

Breaking Changes

• getStoreTreeProof now returns StoreTreeProof message instead of Buffer

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[antouhou]

Nice!