chore(auth): Record email template in statsd metric

[dschom]

Because

• We want to know graph the types of email being sent

This pull request

• Adds the email template name to the statsd metric

Issue that this pull request solves

Closes: FXA-14142

Checklist

Put an x in the boxes that apply

• My commit is GPG signed.
• If applicable, I have modified or added tests which pass locally.
• I have added necessary documentation (if appropriate).
• I have verified that my changes render correctly in RTL (if appropriate).
• I have manually reviewed all AI generated code.

How to review (Optional)

• Key files/areas to focus on:
• Suggested review order:
• Risky or complex parts:

Screenshots (Optional)

Please attach the screenshots of the changes made in case of change in user interface.

Other information (Optional)

Any other information that is important to this pull request.

[vbudhram]

There is roughly 30+ email templates, proably fine for cardinality