HDDS-12057. Handle '/' in key names for the readreplicas command

[ptlrs]

What changes were proposed in this pull request?

Key names may include arbitrary number of / characters, such as /volumename/bucketname/test1/test2.

The read-replicas command assumes key names will be single level or not include any / characters. This results in failures when the command is run on multilevel keys.

This PR flattens the keynames by replacing / with _.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-12075
Also see discussion in #7693

How was this patch tested?

Manual testing:

bash-5.1$ ozone debug --verbose read-replicas /ockrwvolume/ockrwbucket/test1/test2/1
Volume Name : ockrwvolume
Bucket Name : ockrwbucket
Key Name : test1/test2/1
Creating directory : ockrwvolume_ockrwbucket_test1_test2_1_20250122073427
Successfully created!
Writing : test1_test2_1_block1_ozone-datanode-1.ozone_default
Writing manifest file : test1_test2_1_manifest

bash-5.1$ cd ockrwvolume_ockrwbucket_test1_test2_1_20250122073427/

bash-5.1$ ls -alht
total 1.1M
-rw-r--r--  1 hadoop hadoop  365 Jan 22 07:34 test1_test2_1_manifest
drwxr-xr-x  4 hadoop hadoop  128 Jan 22 07:34 .
-rw-r--r--  1 hadoop hadoop 1.0M Jan 22 07:34 test1_test2_1_block1_ozone-datanode-1.ozone_default
drwxr-xr-x 25 hadoop hadoop  800 Jan 22 07:34 ..

bash-5.1$ cat test1_test2_1_manifest 
{
  "filename" : "ockrwvolume/ockrwbucket/test1/test2/1",
  "datasize" : 1048576,
  "blocks" : [ {
    "blockIndex" : 1,
    "containerId" : 1,
    "localId" : 115816896921600001,
    "length" : 1048576,
    "offset" : 0,
    "replicas" : [ {
      "hostname" : "ozone-datanode-1.ozone_default",
      "uuid" : "5e14c3a9-2a94-490a-a34c-a657354c1198"
    } ]
  } ]

CI: https://github.com/ptlrs/ozone/actions/runs/12903408829

[dombizita]

Thank you for fixing this @ptlrs, it looks good to me!

[adoroszlai]

Thanks @ptlrs for the patch, @dombizita for the review.