Returns the value from a storage position at a given address, or in other words, returns the state of the contract's storage, which may not be exposed via the contract's methods.
Params - a string array containing (required):
DATA(hex string, required), 20 Bytes - address of the storage.
QUANTITY(hex string, required)- integer of the position in the storage.
QUANTITY|TAG(hex string|string, required)- integer block number in hex string format, or the string
"pending", see the default block parameter
DATA(hex string) - the value at this storage position.