rpc: adjust getversion RPC response
Reference implementation includes `initialgasdistribution` as integer
value with decimals.
C# response:
```
{
"id": 1,
"jsonrpc": "2.0",
"result": {
"nonce": 1677922561,
"protocol": {
"addressversion": 53,
"initialgasdistribution": 5200000000000000,
"maxtraceableblocks": 2102400,
"maxtransactionsperblock": 512,
"maxvaliduntilblockincrement": 5760,
"memorypoolmaxtransactions": 50000,
"msperblock": 15000,
"network": 860833102,
"validatorscount": 7
},
"tcpport": 10333,
"useragent": "/Neo:3.1.0/",
"wsport": 10334
}
}
```
Neo-Go response:
```
{
"id": 1,
"jsonrpc": "2.0",
"result": {
"network": 860833102,
"nonce": 2847278838,
"protocol": {
"addressversion": 53,
"initialgasdistribution": "52000000",
"maxtraceableblocks": 2102400,
"maxtransactionsperblock": 512,
"maxvaliduntilblockincrement": 5760,
"memorypoolmaxtransactions": 50000,
"msperblock": 15000,
"network": 860833102,
"validatorscount": 7
},
"tcpport": 10333,
"useragent": "/NEO-GO:0.98.2/"
}
}
```
1c6afe402f