Report backend improvements

[nebfield]

Description of feature

Some things to improve building and updating the output report:

• Use renv to capture dependencies in a lock file to improve stability / reproducibility (I'm manually building container images currently)

These won't affect the content of the report but instead change how the report is built

[smlmbrt]

I'd prefer to not make a package - I like that it's easy to see and edit the report in this repository

[smlmbrt]

Also we need to version the report environment, using dev causes problems for new runs of the pipeline:

pgsc_calc/conf/modules.config

Lines 61 to 67 in 3b7ebcc

	withLabel: report {
	ext.conda = "$projectDir/environments/report/environment.yml"
	ext.singularity = 'oras://dockerhub.ebi.ac.uk/gdp-public/pgsc_calc/singularity/report'
	ext.singularity_version = ':dev'
	ext.docker = 'dockerhub.ebi.ac.uk/gdp-public/pgsc_calc/report'
	ext.docker_version = ':dev'
	}