Add context-aware number formatting for '1' in German

[coderabbitai]

There is a need to add context-aware number formatting for the number '1' in German. Currently, '1' is always translated as 'ein', but in German:

• 'eins' is used when the number stands alone
• 'ein' is used before nouns
• 'eine' is used before feminine nouns

Original PR: #1
Comment: #1 (comment)

Requested by: @JarbasAl