Tag normalization: normalize numbers in tags

[Tiendil]

Examples:

• seventy-six -> 76
• viii → 8

Notes:

• Let's check other possible notations.
• What to do with hexademical, octo, and other notations?
• What to do with I, which can be a roman numeral or a pronoun?
• What to do with V, which can be a roman numeral or a letter that we currently use as a separator in the splitter tag normalizer?

Produced as the result of gh-56

Internal task id: ff-506