rpk: sandbox mode: default and container mode

[r-vasquez]

Cover letter

Introducing --sandbox <mode> mode options: default and container

For full context, see PRD: https://docs.google.com/document/d/1qC6K0xvC3i3JgI-LMAWCyWlxQZ8KvM8ABthujWFDQ74

Usage

The user can either set --sandbox (alias for --sandbox default) or --sandbox container

# Default Mode:
$ rpk redpanda start --sandbox
$ rpk redpanda start --sandbox=default
$ rpk redpanda start --sandbox default

# Container Mode:
$ rpk redpanda start --sandbox=container
$ rpk redpanda start --sandbox container

# Mode Validation:
$ rpk redpanda start --sandbox foo
Error: unrecognized sandbox type "foo", use --sandbox=help for more info"

Documentation

$ rpk redpanda start --sandbox help
Sandbox mode sets relevant properties for local development or 
test container usage.

--sandbox
    Flags:
        * --overprovisioned
        * --reserve-memory 0M
        * --check=false
    Cluster Properties:
        * topic_partitions_per_shard: 1000
        * group_topic_partitions: 3
        * auto_create_topics_enabled: true
        * storage_min_free_bytes: 10485760 (10Mb)

--sandbox container
    Flags:
        * --overprovisioned
        * --reserve-memory 0M
        * --check=false
        * --smp 1
        * --unsafe-bypass-fsync
    Cluster Properties:
        * topic_partitions_per_shard: 1000
        * group_topic_partitions: 1
        * auto_create_topics_enabled: true
        * storage_min_free_bytes: 10485760 (10Mb)

After redpanda starts you can modify the cluster properties using:
    rpk config set <key> <value>

Backport Required

• [x] v22.2.x

UX changes

• overprovisioned is now enabled by default when Redpanda.DeveloperMode is enabled (redpanda.developer_mode : true in redpanda.yaml)

Release notes

[BenPope]

I don't know what happened to container mode, but this might be relevant. It doesn't work on mac, which is why I didn't doc it: https://github.com/redpanda-data/vtools/pull/256

[twmb]

--mode=container

PR was closed due to conflicting things, this was reopened