4.x: bring server side and client side timeout for admin queries in line

[dkropachev]

Currently there are two distinct configurations for server side (DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT) and client side (DefaultDriverOption.CONTROL_CONNECTION_TIMEOUT) timeouts for admin queries.

both these timeouts have to have similar value, client-side could be a bit higher to offset network delay.

Current defaults:
DefaultDriverOption.CONTROL_CONNECTION_TIMEOUT - 5 seconds
DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT - 20 seconds

A huge no, no, we need to fix it.

[Bouncheck]

Why do we think those timeouts affect each other?
METADATA_SCHEMA_REQUEST_TIMEOUT is specific timeout for metadata schema requests and is both client and server side now, I believe since #312

This timeout is directly applied here:

java-driver/core/src/main/java/com/datastax/oss/driver/internal/core/metadata/schema/queries/CassandraSchemaQueries.java

Line 202 in c85f7b9

return AdminRequestHandler.query(channel, query, timeout, pageSize, logPrefix).start();

and its value is set here:

java-driver/core/src/main/java/com/datastax/oss/driver/internal/core/metadata/schema/queries/CassandraSchemaQueries.java

Line 76 in c85f7b9

this.timeout = config.getDuration(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT);

CONTROL_CONNECTION_TIMEOUT is a separate timeout that does not conflict with this one.