Add schema validation for assemblysubmit and genomesubmit workflows

### Description of feature

Currently schemas are not validated. The task is to change PIPELINE_INITIALISATION subworkflow to use `validateSamplesheet` function from nf-utils. Schema should be set depending on the pipeline mode executed. Also worth checking existing schemas and improving where needed. 
assets/schema_input_assembly.json
assets/schema_input_genome.json