feat: add OCL Reaction editor module

[targos]

No description provided.

[targos]

@lpatiny I implemented what we discussed. I created two testcases:

• "OpenChemlib reaction editor" to showcase in/out variables and actions
• "OpenChemlib reaction in-place editor" to showcase the in-place modification

[targos]

Two notes:

• The buttons to import reactant and product have the same icon
• The ReactionEncoder from OCL always returns null if there isn't a least one reactant and one product.

[lpatiny]

And there is also a nice feature of JSME that allows to easily duplicate a reagent that will be missing a lot. Well in fact there is another way. You can duplicate a reagent using SHIFT key. I guess we can educate the users.

Are we able to associate the ESC key to select the 'lasso' option ? This could help to quickly select a reagent and duplicate it.

Related to:

• Possibility to have 'global' shortcuts ? cheminfo/openchemlib-js#335

Nothing to do with this PR.

[lpatiny]

• The ReactionEncoder from OCL always returns null if there isn't a least one reactant and one product.

Quite annoying indeed:

• Reaction editor and missing reagents or products Actelion/openchemlib#150

We will check what Thomas answers but I could write a temporary code in openchemlib-js to overload toRXN.

[lpatiny]

I started to write the userguide in the meantime: https://docs.c6h6.org/docs/eln/uuid/ocl-editor-reactions

[targos]

@lpatiny I let you test again and merge when you want.