Updates to ONIX techniques

[gautierchomel]

• Removes ONIX list 81 code 24 from possible option to determine presence of pre recorded audio necessary for understanding the content
• Adds ONIX list 81 code 29 Partial performance – video
• Corrects list 81 code 25 Narrative animation
• Adds ONIX list 81 code 28 Other video
• Define chemical_formula_as_mathml wich was missing
• Applies American English for Visualize
• Adds presence check for Charts and Diagrams

Fixes #286, #284, #277, #283, #287