Add snap training

[mahesh-panchal]

Change log:

• [x]: Workflow renamed: AugustusTraining -> AbinitioTraining.
• [x]: Update README.
• [x]: Workflow parameter renamed: augustus_training_species -> species_label.
• [x]: Add Snap training.
• [x]: AGAT updated to 0.2.3.
• [x]: Updated test profile.

Tests: nextflow run -profile nbis,conda,test ${GIT_REPO}/AbinitioTraining ✔️ nextflow run -profile nbis,singularity,test ${GIT_REPO}/AbinitioTraining ✔️