Support dotLottie format.

DotLottie is a new standard for the Lottie file format.
Essentially, it's a compilation of animations that encapsulates multiple Lottie animations into one zipped file.
More information on its structure can be found here:
https://dotlottie.io/structure/#dotlottie-structure

This implementation borrows certain elements from the unzipping functionality
found at https://github.com/kuba--/zip,
an open-source project distributed under the No License.

Tests have been carried out using the file '1st_animation.lottie'
located in the 'examples/resource' directory.