[ISSUE-3149] identity management - add clarification to the Name field

[florentos17]

i am new to the repository tmail-flutter, but i saw this issue and it seemed pretty straightforward so i wanted to give it a try.

i changed the field label and the documentation, and corrected a few typos while i was at it. i apologize if i did things wrong !

[dab246]

Should be use lowerCamelCase style for name

[florentos17]

fixed !
actually, many similar getters are in snake_case style, for example:

tring get reply_to {
    return Intl.message(
        'Reply to',
        name: 'reply_to');
  }

  String get bcc_to {
    return Intl.message(
        'Bcc to',
        name: 'bcc_to');
  }

do you want me to change those as well ?