Handle more information units (Mi, Gi, Ti), add rabbitmq.conf validation for IU values

[michaelklishin]

This revisits the information system conversion,
that is, support for suffixes like GiB, GB.

When configuration values like disk_free_limit.absolute, vm_memory_high_watermark.absolute are set, the value can contain an information unit (IU) suffix.

We now support several new suffixes and the meaning a few more changes.

First, the changes:

• k, K now mean kilobytes and not kibibytes
• m, M now mean megabytes and not mebibytes
• g, G now means gigabytes and not gibibytes

This is to match the system used by Kubernetes.
There is no consensus in the industry about how
"k", "m", "g", and similar single letter suffixes
should be treated. Previously it was a power of 2, now a power of 10 to align with a very popular OSS project that explicitly documents what suffixes it supports.

Now, the additions:

• T, TB (terabytes) and Ti, TiB (tebibytes)
• P, PB (petabytes) and Pi, PiB (pebibytes)

Finally, the node will now validate these suffixes at boot time, so an unsupported value will cause
the node to stop with a rabbitmq.conf validation
error.

The message logged will look like this:

2024-01-15 22:11:17.829272-05:00 [error] <0.164.0> disk_free_limit.absolute invalid, supported formats: 500MB, 500MiB, 10GB, 10GiB, 2TB, 2TiB, 10000000000
2024-01-15 22:11:17.829376-05:00 [error] <0.164.0> Error preparing configuration in phase validation:
2024-01-15 22:11:17.829387-05:00 [error] <0.164.0>   - disk_free_limit.absolute invalid, supported formats: 500MB, 500MiB, 10GB, 10GiB, 2TB, 2TiB, 10000000000

Closes #10310.

How to Test It

Using the following rabbitmq.conf lines:

disk_free_limit.absolute = 5LOLWUT

# disk_free_limit.absolute = 5G

# disk_free_limit.absolute = 5GB

# disk_free_limit.absolute = 5Gi

# disk_free_limit.absolute = 5GiB

# disk_free_limit.absolute = 5000000000

bazel run broker RABBITMQ_ENABLED_PLUGINS=rabbitmq_management RABBITMQ_CONFIG_FILE=/path/to/disk_free_limit.absolute.conf

Then run rabbitmq-diagnostics status against it:

./bazel-bin/broker-home/sbin/rabbitmq-diagnostics status

[michaelklishin]

For context: K8S docs, #10308.