* Update TestProject Fixture to include GoogleService-Info.plist resource bsaed on 2.18.0 generator
* Update TestProject fixture to include an Info.plist file named 'App-Info.plist' to simulate scenario in #945
* Resolve INFOPLIST_FILE values upfront ahead of resolving all source files for a target
* fixup! Resolve INFOPLIST_FILE values upfront ahead of resolving all source files for a target
* fixup! Resolve INFOPLIST_FILE values upfront ahead of resolving all source files for a target
* Refactor SourceGenerator to remove some redundant arguments on internal methods when generating source files in a target
* Update SourceGenerator to accept '[Path: BuildPhaseSpec]' of preferred build phases in order to prioritise over 'default' value. Remove explicit Info.plist check from SourceGenerator. Update PBXProjGenerator to inject hash of build phases for resolved INFOPLIST_FILE values. Update SourceGeneratorTests to comply with change where only the FIRST Info.plist is excluded from copy bundle resources build phase, additionally resolve absolute path
* Ensure project.basePath is always absolute when resolving Info.plist path relative to project
* Add test coverage in SourceGeneratorTests.swift
* Update CHANGELOG.md
* Reword CHANGELOG.md