feat: indicate origin of mets and rxns added in recent updates

[BenjaSanchez]

Following what we made in PR #156, we should include both in metNotes or rxnNotes why were the corresponding mets/rxns added for the following past updates to the model:

• SLIMEr update: For mets: "pseudo-metabolite part of the SLIMEr formalism (PR Feat/SLIME rxns #112)". For rxns: "pseudo-reaction part of the SLIMEr formalism (PR Feat/SLIME rxns #112) - units in mg/gDWh"
• New annotation update: For both mets and rxns indicate "added after new annotation (PR Feat/DBnewAnnotation2 #142)"
• Biolog update: For both mets and rxns indicate " added after the Biolog update (PR Biolog_Update #149)"

For consistency, we should also update the notes added in #156:

• Metabolomics update: For mets: "added from metabolomics data (PR Metabolomics update #156)". For rxns: "metabolites observed in metabolomics data (PR Metabolomics update #156)"

I hereby confirm that I have:

• Done this analysis in the master branch of the repository
• Checked that a similar issue does not exist already
• If needed, asked first in the Gitter chat room about the issue

[BenjaSanchez]

update: this was completed in PR #170, this issue will be closed on next release