allow underscores in cell names

[dimalvovs]

currently hd method fails if there are underscores in the cell names due to the regex specified in https://github.com/DeshpandeLab/SpaceMarkers/blob/ead294d01081609773f6c055ecdbadf1cfe0f772/R/utils.R#L390C9-L390C54

reproducible example

  lrpairs <- read.csv(file = sprintf("%s/lr_pairs.csv", "~/data/lr_scores_tesdata/"), row.names = 1)
  ligand_scores <- read.csv(file = sprintf("%s/ligand_scores.csv", "~/data/lr_scores_tesdata/"), row.names = 1)
  receptor_scores <- read.csv(file = sprintf("%s/receptor_scores.csv", "~/data/lr_scores_tesdata/"), row.names = 1)
  calculate_lr_scores(ligand_scores,receptor_scores,lr_pairs=lrpairs, method = "geometric_mean", weighted = TRUE)

receptor_scores.csv
ligand_scores.csv
lr_pairs.csv

since cell types may have underscores in them, it would be good to change to a more robust regex.