Add rdb-cli to internal utilities list

[moticless]

Summary

• Adds the rdb-cli utility (from https://github.com/redis/librdb) to the Internal utilities table across all Redis Software CLI utilities pages.

Test plan

• Verify rendered pages list rdb-cli in the internal utilities table on each affected version.

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Note

Low Risk
Low risk documentation-only change that adds a new row/link to existing reference tables with no product or code behavior impact.

Overview
Adds rdb-cli (linking to https://github.com/redis/librdb) to the Internal utilities table on Redis Software/Enterprise CLI utilities reference pages, describing it as a tool to parse and convert RDB files across the unversioned page and versions 7.4, 7.8, and 7.22.

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[rrelledge]

Thank you!

[rrelledge]

@moticless Can you also please sign the CLA so I can merge this PR? #3364 (comment)