Change model lazy-assignment property functions to return "Unknown"

[AetherUnbound]

Based on discussion in #91, we should change the other functions on the Officer model to return "Unknown" directly rather than default to it in the template.

Here are the functions used within the template:

OpenOversight/OpenOversight/app/templates/list_officer.html

Lines 179 to 193 in ba37bf7

	<dd>{{ officer.job_title()|default('Unknown') }}</dd>
	<dt>Unit</dt>
	<dd>{{ officer.unit_descrip()|default('Unknown') }}</dd>
	<dt>Currently on the Force</dt>
	<dd>{{ officer.currently_on_force() }}</dd>
	<dt>Known incidents</dt>
	<dd>{{ officer.incidents | length }}</dd>
	</dl>
	</div>
	<div class="col-md-6 col-xs-6">
	<dl>
	<dt>Race</dt>
	<dd>{{ officer.race_label()|default('Unknown')|lower|title }}</dd>
	<dt>Gender</dt>
	<dd>{{ officer.gender_label()|default('Unknown') }}</dd>

The functions to modify would be Officer::job_title, Officer::unit_descrip, Officer::race_label, and Officer::gender_label.

[rsk2]

Hi @AetherUnbound, hope you're doing well. I am not sure if you remember but I have contributed in the past to this repository.

Can I help with this issue?