Expose lavasearch under the api scope

[freyacodes]

I am encountering this compiler error with LavaSrc as a dependency:

e: Supertypes of the following classes cannot be resolved. Please make sure you have the required dependencies in the classpath:
    class com.github.topi314.lavasrc.deezer.DeezerAudioSourceManager, unresolved supertypes: com.github.topi314.lavasearch.AudioSearchSourceManager
Adding -Xextended-compiler-checks argument might provide additional information.

e: file:///home/freya/git/tenshi/tenshi/src/main/java/fredboat/config/AudioPlayerManagerConfiguration.kt:296:74 Cannot access 'com.github.topi314.lavasearch.AudioSearchSourceManager' which is a supertype of 'com.github.topi314.lavasrc.deezer.DeezerAudioSourceManager'. Check your module classpath for missing or conflicting dependencies

The problem appears to be that AudioSearchSourceManager is unavailable as a transitive dependency because of the implementation scope. I have not tested this PR, however putting lavasearch into scope in my project fixes the compile error.