[Audio] Add GlobalAveragePooling1D layer

[zaleslaw]

We are missing some layers to support the export of models from Keras fully. One of them is the GlobalMaxPooling1D layer.

Add a layer class, write documentation for it, write a test for it, try, if possible, create a small trainable network with it (in your own GitHub) and attach a link here in the comments.

The layer should be placed here

As a reference implementation, the GlovalAvgPool2D layer could be used, but feel free to improve it!

If some refactoring to pooling layers could be applied, please, try to do it!

Also, support for export and import of layer in JSON format should be added (see ModelLoader.kt and ModelSaver.kt)

A detailed description of the layer can be found here

[therealansh]

Hey @zaleslaw , interesting project will be coming up with this PR soon. Might have some questions, is there any community server like discord or a community chatroom?

[zaleslaw]

Hi, @therealansh , thanks for joining!
Feel free to ask here, or raise a question in Discussion chapter
Also, you could register in Kotlin slack and join #kotlindl channel and find me by nickname @zaleslaw