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.
