Remove age method from person class and replace references in calculate_md502_cr_part_m_line_1

[embarnard]

Link to pivotal/JIRA issue

• e.g. link

Is PM acceptance required? (delete one)

• No - merge after code review approval

Reminder: merge main into this branch and get green tests before merging to main

What was done?

• We changed how we calculate DOB in this story; this age method does not reflect the differences in guidelines across states and should be removed and references instead should use the calculate_age method or other methods that ultimately use it

How to test?

• should function the same, current tests for this method still pass

[github-actions]

Heroku app: https://gyr-review-app-4921-27899f0b120e.herokuapp.com/
View logs: heroku logs --app gyr-review-app-4921 (optionally add --tail)

[powersurge360]

Had to look up the XOR operator cause I forgot but looks good!