Changes the default socket and connection timeouts for the rest
client from 10 seconds to the more generous 30 seconds.
Defaults reindex-from-remote to those timeouts and make the
timeouts configurable like so:
```
POST _reindex
{
"source": {
"remote": {
"host": "http://otherhost:9200",
"socket_timeout": "1m",
"connect_timeout": "10s"
},
"index": "source",
"query": {
"match": {
"test": "data"
}
}
},
"dest": {
"index": "dest"
}
}
```
Closes#21707
[DOCS] add java REST client docs
Add some docs on how to get started with the Java REST client, some common configuration that may be needed and the sniffer component.
Nik Everett
Luca Cavanna