refactor depsearch

[neha170]

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• [X] The toolchain has been rebuilt successfully (or no changes were made to it)
• [X] The toolchain/worker package manifests are up-to-date
• [X] Any updated packages successfully build (or no packages were changed)
• [X] Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• [X] Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• [X] All package sources are available
• [X] cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• [X] LICENSE-MAP files are up-to-date (./SPECS/LICENSES-AND-NOTICES/data/licenses.json, ./SPECS/LICENSES-AND-NOTICES/LICENSES-MAP.md, ./SPECS/LICENSES-AND-NOTICES/LICENSE-EXCEPTIONS.PHOTON)
• [X] All source files have up-to-date hashes in the *.signatures.json files
• [X] sudo make go-tidy-all and sudo make go-test-coverage pass
• [X] Documentation has been updated to match any changes to the build system
• [X] If you are adding/removing a .spec file that has multiple-versions supported, please add @microsoft/cbl-mariner-multi-package-reviewers team as reviewer (Eg. golang has 2 versions 1.18, 1.21+)
• [X] Ready to merge

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Summary

refactor depsearch into tool and utils

Change Log

• refactor depsearch into tool and utils
• part of series of similar changes across the toolkit

Does this affect the toolchain?

NO

Test Methodology

• Built package successfully with REBUILD_TOOLS=y
• Built all tools (make go-tools REBUILD_TOOLS=y)
• Ran depsearch tool to make sure it runs