Modify the gRPC interface to start including streaming block ranges

[linuskendall]

• subscribe on block from block A to block N
• filter blocks by account mention
• subscribe to transactions from slot A to slot N

[linuskendall]

Lets try to follow as closely as we can to the dragon's mouth API:
https://docs.triton.one/project-yellowstone/dragons-mouth-grpc-subscriptions#subscribe-to-blocks

methods could be:

streamBlocks
streamTransactions (this will need a filter)

[anjor]

if stream blocks looks good i can open similar PR for streamTransactions

[linuskendall]

streamTransactions:

message SubscribeRequestFilterTransactions {
  optional bool vote = 1;
  optional bool failed = 2;
  repeated string account_include = 3;
  repeated string account_exclude = 4;
  repeated string account_required = 6;
}

For the accounts filters:

For transactions, if all fields are empty, then all transactions are broadcasted. Otherwise, fields work as logical AND, and values in arrays as logical OR. You can include/exclude vote transactions and include/exclude failed transactions.

If account_include is not specified, then iterate through all the blocks and return every transaction that doesn't mention account_exclude and that match vote/failed filter.

If account_include is specified, then lookup in the get-signatures-for-address index to get all the signature+slot combos and then start reading these transactions one by one, applying the other filters account_exclude, account_include.

To be able to do this we need to :

• Add slot number to gsfa index (@gagliardetto)
• In the gsfa reader we only need to construct readers for the epochs that match the slots requested (

  yellowstone-faithful/multiepoch-getSignaturesForAddress.go

  Lines 19 to 20 in 6227dd8

  	func (ser *MultiEpoch) getGsfaReadersInEpochDescendingOrder() ([]*gsfa.GsfaReader, []uint64) {
  	ser.mu.RLock()

  (@anjor )
• Create a new method https://github.dev/rpcpool/yellowstone-faithful/blob/main/gsfa/gsfa-read-multiepoch.go to read transactions between two slot numbers (read 1000 chunks, check if we've reached the slot number, then read another 1000 chunks if we need to and so on).

	gsfaIndexes, _ := multi.getGsfaReadersInEpochDescendingOrder(startSlot, endSlot)
	if len(gsfaIndexes) == 0 {
		return &jsonrpc2.Error{
			Code:    jsonrpc2.CodeInternalError,
			Message: "getSignaturesForAddress method is not enabled",
		}, fmt.Errorf("no gsfa indexes found")
	}

	gsfaMulti, err := gsfa.NewGsfaReaderMultiepoch(gsfaIndexes)
	if err != nil {
		return &jsonrpc2.Error{
			Code:    jsonrpc2.CodeInternalError,
			Message: "Internal error",
		}, fmt.Errorf("failed to create gsfa multiepoch reader: %w", err)
	}

      	foundTransactions, err := gsfaMulti.GetSlotRange(
		ctx,
		pk,
		limit,
		startSlot,
		endSlot,
       )

Remember:

• We will get transactions going backwards