cassandra-stress: Make default repl. strategy NetworkTopologyStrategy

[elcallio]

Fixes #400

Switch default strategy to scylla preferred default.

[bhalevy]

@scylladb/scylla-tools-maint please merge

[denesb]

https://github.com/scylladb/scylladb/pull/19818

[bhalevy]

@dani-tweig can you please add backport labels for 6.1 and 6.2 (and we probably also need backport labels for enterprise branch in scylla-enterprise-tools-java)?

This needs backport to 6.1 and 6.0. Cc @denesb

[denesb]

@bhalevy why should we backport this? I need a scylla issue with a problem the this PR and the backport would fix.

[bhalevy]

@bhalevy why should we backport this? I need a scylla issue with a problem the this PR and the backport would fix.

The issue is https://github.com/scylladb/scylla-tools-java/issues/400.

We want to use NetworkTopologyStrategy by default for 2 reasons:

1. To enable tablets for cassandra-stress when they are enabled by default - this is the motivation for the backport
2. SimpleStrategy was deprecated a LONG time ago, and it's about time we stop using it by default in all of our tools (no other reason is really required) - this does not require backport.

[denesb]

Backports:

• 6.1: https://github.com/scylladb/scylladb/pull/20199
• 6.0: https://github.com/scylladb/scylladb/pull/20200