Add "methodics" entity

[jandevaty]

A "methodics" entity would be very usefull to desribe tools and methods that are repeatedly used for data collection/processing. Right now measurements/simulations/soil samples have only the 'description' property that needs to be writen/copy-pasted for every new instance. A "methodology" entity instance would be just referenced by other entities and used wherever appropriate.
Basic set of properties: name_cz, name_en, description_cz, description_en, note_cz, note_en, files_path, links (list of urls to equipment used or external methodics description
many-to-one relation with entities: sequence, run, soil_sample, measurement, record