Event Indexing Issue causing UNIQUE constraint violation in Firefly Core

### Summary:
An issue has been identified in the interaction between the Firefly-fabconnect and Firefly Core services. Firefly-fabconnect is not correctly populating the transactionIndex and eventIndex for events within a single block, causing a UNIQUE constraint violation in the Firefly Core events table.

### Details:
Firefly Core has a UNIQUE constraint on a set of fields for its events table. Each event processed by Firefly Core should have a unique combination of these fields to avoid conflicts. Firefly-fabconnect is responsible for generating and assigning unique transactionIndex and eventIndex values for each event in a block. However, it has been observed that Firefly-fabconnect is not correctly populating these indices.

Event creation logic in fabconnect:
```
internal/events/subscription.go:133

event := &eventsapi.EventEntry{
ChaincodeId: ccEvent.ChaincodeID,
BlockNumber: ccEvent.BlockNumber,
TransactionId: ccEvent.TxID,
EventName: ccEvent.EventName,
Payload: ccEvent.Payload,
}
```
Debugger inspector representation of the event in fabconnect:

```
event = {*api.EventEntry | 0x1400001b6c0}
ChaincodeId = {string} "token-erc-721-v1"
BlockNumber = {uint64} 81
TransactionId = {string} "421b2cb8ce1bcc1332712572b63124e5a1fa70e32eb48626703a56f39ec94059"
TransactionIndex = {int} 0
EventIndex = {int} 0
EventName = {string} "TokenMinted"
Payload = {interface{} | []uint8} len:278, cap:288
Timestamp = {int64} 1684224393739164000
SubID = {string} ""
```

What is received in Firefly Core:

```
messages = {[]interface{}} len:2, cap:2
0 = {interface{} | map[string]interface{}}
0 = transactionIndex -> 0
1 = timestamp -> 1684154093804696000
2 = chaincodeId -> token-erc-721-v1
3 = blockNumber -> 80
4 = transactionId -> cfdf3b5bf26014af280ad88d223db65f4efbe59e92f41263ca5006995a9078d1
5 = eventIndex -> 0
6 = eventName -> TokenMinted
7 = payload -> eyJ0byI6Ing1MDk6OkNOPWNyZWF0b3IsT1U9Y2xpZW50OjpDTj1mYWJyaWNfY2Eub3JnMS5leGFtcGxlLmNvbSxPVT1IeXBlcmxl
8 = subId -> sb-c85b1648-8020-4c68-61fb-cb2f26856e93
1 = {interface{} | map[string]interface{}}
0 = chaincodeId -> token-erc-721-v1
1 = blockNumber -> 80
2 = transactionId -> 638aaa7b5ee53edcd104e98f84b4d8c3fb7a311bb90525f0144ac7cda92ea891
3 = eventIndex -> 0
4 = eventName -> TokenMinted
5 = timestamp -> 1684154093804696000
6 = subId -> sb-c85b1648-8020-4c68-61fb-cb2f26856e93
7 = transactionIndex -> 0
8 = payload -> eyJ0byI6Ing1MDk6OkNOPWNyZWF0b3IsT1U9Y2xpZW50OjpDTj1mYWJyaWNfY2Eub3JnMS5leGFtcGxlLmNvbSxPVT1IeXBlcmxl
```

The error that is thrown:

`[2023-05-16T11:09:31.707+03:00] ERROR SQL insert failed: UNIQUE constraint failed: blockchainevents.namespace, blockchainevents.listener_id, blockchainevents.protocol_id sql=[ INSERT INTO blockchainevents (id,source,namespace,name,protocol_id,listener_id,output,info,timestamp,tx_type,tx_id,tx_blockchain_id) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12) ]: UNIQUE constraint failed: blockchainevents.namespace, blockchainevents.listener_id, blockchainevents.protocol_id dbtx=KzK541m0 ns=default pid=48305 role=event-manager`

### Impact:
This issue is preventing Firefly Core from processing multiple events of the same type within a single block. This could potentially lead to loss of data or incomplete data processing, impacting the overall functionality and data integrity of the system.

### Recommended Actions:
The root cause of the issue appears to be with Firefly-fabconnect's event indexing. It is recommended to investigate why Firefly-fabconnect is not correctly populating transactionIndex and eventIndex for each event within a block. Once identified, a fix should be implemented to ensure that each event in a block is assigned a unique pair of indexes. This will allow Firefly Core to process and insert all events correctly without violating the UNIQUE constraint on its events table.