Add complete benchmark number (include component number in the benchmark number as well)

[samshara]

feedback from @steph-gm:

Assessment tab:
• Add the complete benchmark number (for example 1.1., 1.2.... 2.1, 2.2.... 3.1, 3.2... etc.). At the moment only one number is appearing, so it can be complicated to identify them without relating them to the component number.

Originally posted by @tovari in IFRCGo/go-web-app#447 (comment)