chore: refactor case_file.service update transaction boundary

[marqueone-ps]

Description

Clean up and reorganization of code by functionality. Update to transaction boundary to ensure all code for creating and updating feature is in a single transaction

Task # CE-584

Type of change

Please delete options that are not relevant.

• [x] code organization
• [x] move transaction boundary

How Has This Been Tested?

• [x] existing tests

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