fix: custom qualifier annotations not generating qualifier at injection point

[skyecodes]

Following #176, after some testing on v2.0.0-Beta3, I found that the custom qualifier annotations do not generate the qualifier when used to inject a parameter, which would in most cases cause a NoDefinitionFoundException at runtime.

This PR addresses the issue by correctly generating the corresponding qualifier.

Example:

@Named
public annotation class WhiteBunny

@Qualifier
public annotation class BlackBunny

@Single
public class Farm(@WhiteBunny public val whiteBunny: Bunny, @BlackBunny public val blackBunny: Bunny)

Generated code before fix:

single() { _ -> org.koin.example.animal.Farm(whiteBunny=get(),blackBunny=get()) }

Generated code after fix:

single() { _ -> org.koin.example.animal.Farm(whiteBunny=get(qualifier=org.koin.core.qualifier.StringQualifier("org.koin.example.animal.WhiteBunny")),blackBunny=get(qualifier=org.koin.core.qualifier.StringQualifier("org.koin.example.animal.BlackBunny"))) }

This test case has been added to the existing unit test.