Missing loinc codes for CH4 (and H2S) breath tests

[lpg-tech]

There is only one general LOINC code for H2 breath test panel
50584-2 "Lactose challenge (hydrogen breath test) panel - Exhaled gas"
but we got all LOINC codes for H2 and CH4 breathtests in the time axis.

It would be nice to get also a general LOINC code for CH4 (and H2S ?) breath test. Since a request at the Regenstrief Institute will probably take longer, we will leave the breath test example as it is currently implemented.

Request on Regenstrief Instutute done 8.4.2024:
https://loinc.org/submissions/queue/ Set ID 7220, ID 68741