Locale: e-mail + TLD

[McLaynV]

The following changes are implemented

Locale changes:

• Replaced E-mail with Email for consistency - see the counts below
• Replaced placeholder: [email protected] with placeholder: [email protected] as TLD stands for top-level domain

# grep -ir e-mail . | wc -l
7

# grep -ir email . | wc -l
84

Changes in the user interface:

Minor locale fixes.

Checklist when submitting a final (!draft) PR

• Commits are tidied up, squashed if needed and follow guidelines in CONTRIBUTING.md
• Code builds
• All existing tests pass
• All new critical code is covered by tests
• PR is linked to the relevant issue(s)
• Rebased with the target branch