chore: webhook timer coverage in mutate-processor test

[cmwylie19]

Description

This is very hard to test because the Capability does not have actual bindings. Because of that the test stops here and returns early. The only meaningful tests I could do was to ensure the timer start and stop were called.

There is already too much mocking in this file I cannot get any assertions to pass for base64 calls here.

UPDATE: was able to validate the first decodeData was called by shuffling files around and mocking the call in mutate-process.test.ts. The rest of the test is untestable due to no bindings in the capabilities

Needs #1895 to pass.

Related Issue

Fixes #1892

Relates to #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Unit, Journey, E2E Tests, docs, adr added or updated as needed
• Contributor Guide Steps followed