MAtrix enhencements

Improve the coding:

• Cleanup unnecessary files
• delete Rdavidwebservice and post from heatmap 'fucntionnal analysis'
• implement string-db web API (see #17)
• delete functionnal analysis from 'vennDiagram' and replace by send to 'enrichr'
• tranfer heatmap 'functionnal analysis' widget 'into heatmap cluster' widget tab
• update to las R version
• cleanup old/unused packages
• implement renv in place of packrat
• implement enrichr-KG? (see #33)
• implement Gprofiler (see #35)
• reports : https://shiny.posit.co/r/articles/build/generating-reports/