[RM-7040] [linemodel] modify the hard-coded specific line identification

Created on 2022-02-03 12:02:27 by Didier Vibert. % Done: 0

Some lines have a specific treatment (Lya, Balmer rules, Ha, OII,...)
those lines are identified by their hard-coded name, which should thus be the same than the one in the linecatalog.

since the introduction of the new lines catalog format (#6856 ), and the future cleaning of the names (#7034) :

• this identification should now be done through their internal string ID composed as <name><wavelength: 2 decimals><type: A|E>
  see calibration lib code:
  <pre><code class="python">
  def _get_linecatalog_id(self, row):
  wl = round(row.WaveLength,2)
  return row.Name + "" + str(wl) + "" + row.Type
  </code></pre>

=> this raises the question again: should we put the name in this ID ?

• centralize these specifc line identifications in some class or enum, for easier further modifications.