HDDS-11421. Invalid token generated by "ozone dtutil get" command

[echonesis]

What changes were proposed in this pull request?

ozone dtutil get previously generated an empty credentials file when an o3:// or ofs:// URL was used. Only O3fsDtFetcher was registered, so Hadoop dtutil could not find a delegation token fetcher matching the o3 or ofs scheme.

This PR:

• adds and registers OfsDtFetcher for ofs:// URLs;
• adds and registers O3DtFetcher for o3:// URLs;
• maps the OM authority from an o3:// URL to an ofs:// URI and reuses the existing OFS delegation token retrieval path;
• preserves support for OM HA service IDs and direct host/port authorities;
• adds unit tests for scheme handling, URI conversion, token storage, missing authorities, and failed token retrieval;
• adds tests verifying that all Ozone DtFetcher providers can be loaded through ServiceLoader;
• adds secure smoke coverage for generating and printing tokens with both o3:// and ofs:// URLs.

The change is client-side only and does not modify OM behavior or the delegation token format.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-11421

How was this patch tested?

Local Test (Unit Test)

mvn -pl :ozone-filesystem-common test \
 -Dtest=TestOzoneDtFetcher \
 -DskipShade -DskipRecon -DskipDocs

GitHub Actions CI: https://github.com/echonesis/ozone/actions/runs/32243533098

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