Typescript Unittest For Ledger RPC

[stechu]

Add a typescript unittest for ledger RPC.

Unit Test Spec

Use sudo to set the storage to random UTXO and void numbers: for each round add random number (1 to 2) of random (UTXO, EncryptedNote) pairs and a random number (0 to 2) of random VoidNumbers:

• Shards: Add random (UTXO, EncryptedNote) pairs with a random first key and increasing second key
• InsertionOrderedVoidNumbers: Add random VoidNumbers with increasing key

Checkpoint Description:

• receiver_index: [usize; 256]: Lengths of each first key in Shards
• sender_index: usize: Length of InsertionOrderedVoidNumber

Testing correctness of Normal Usage:

1. Add random elements to ledger
2. Select a random checkpoint that's below the current one
3. Pull the latest state and check that it returns the data items (in order!) up to the checkpoint returned in the diff
4. If should_continue == true then pull should be called again with the returned checkpoint (GOTO step 3)
5. If it passes GOTO step 1

Testing correctness of Abnormal Usage: Same as the previous test except try to get from a checkpoint later than the current one. The pull should return nothing.