Refactor functional tests to use JSON comparison (part 1)

Description

This PR updates the first portion of Edge functional tests to use the JSON comparison system. Broadly, it replaces dictionary flattening with JSON comparison. Specific changes:

If flattened dictionary count was applied, then strict collection count checks are applied throughout the JSON validation when using the extensible comparison methods assertExactMatch/assertTypeMatch - that is, the refactor should preserve the same level of strictness for the payload being tested
Everywhere FileManager.default.clearCache() is used, FileManager.default.removeAdobeCacheDirectory() was also added (given Core's new persistence handling)

Questions for reviewers

testSendEvent_receivesResponseEventHandle_sendsResponseEvent_pairedWithTheRequestEventId

Can let requestId = resultNetworkRequests[0].url.queryParam("requestId") ever be nil? Should that be strictly validated? Currently the refactor sets the fallback value to "'

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

[ ] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

[ ] I have signed the Adobe Open Source CLA.
[ ] My code follows the code style of this project.
[ ] My change requires a change to the documentation.
[ ] I have updated the documentation accordingly.
[ ] I have read the CONTRIBUTING document.
[ ] I have added tests to cover my changes.
[ ] All new and existing tests passed.

adobe / aepsdk-edge-ios

Refactor functional tests to use JSON comparison (part 1) #437