Use portfolio_role entity to display and update portfolio member info.

Previously, we were encoding the portfolio_role.user_id as part of the
form data for the portfolio admin page. This was convenient because it
allowed us to easily determine certain display attributes in the
template. Instead, we should rely on the PortfolioRole as the source of
truth for member information. This commit adds:

- Portfolio.owner_role to return the PortfolioRole of the owner
- explicitly passes the PortfolioRole IDs for the PPoC and current user
  to the template
- PortfolioRole.full_name for deriving the member name

templates/fragments/admin/members_edit.html

@@ -1,18 +1,18 @@
 {% from "components/options_input.html" import OptionsInput %}
 
 {% for subform in member_perms_form.members_permissions %}
-  {% set modal_id = "portfolio_id_{}_user_id_{}".format(portfolio.id, subform.user_id.data) %}
-  {% set ppoc = subform.user_id.data == portfolio.owner.id %}
+  {% set modal_id = "portfolio_id_{}_user_id_{}".format(portfolio.id, subform.member_id.data) %}
+  {% set ppoc = subform.member_id.data == ppoc_id %}
   {% set archive_button_class = 'button-danger-outline' %}
 
   <tr {% if ppoc %}class="members-table-ppoc"{% endif %}>
-    <td class='name'>{{ subform.member.data }}
+    <td class='name'>{{ subform.member_name.data }}
       <div>
         {% if ppoc %}
           {% set archive_button_class = 'usa-button-disabled' %}
           <span class='you'>PPoC</span>
         {% endif %}
-        {% if subform.user_id.data == user.id %}
+        {% if subform.member_id.data == current_member_id %}
           {% set archive_button_class = 'usa-button-disabled' %}
           <span class='you'>(<span class='green'>you</span>)</span>
         {% endif %}
@@ -30,7 +30,7 @@
       </a>
     </td>
     {% if not ppoc %}
-      {{ subform.user_id() }}
+      {{ subform.member_id() }}
     {% endif %}
   </tr>
 {% endfor %}

templates/fragments/admin/members_view.html

@@ -1,14 +1,14 @@
 {% for subform in member_perms_form.members_permissions %}
-  {% set ppoc = subform.user_id.data == portfolio.owner.id %}
+  {% set ppoc = subform.member_id.data == ppoc_id %}
   {% set heading_perms = [subform.perms_app_mgmt, subform.perms_funding, subform.perms_reporting, subform.perms_portfolio_mgmt] %}
 
   <tr>
-    <td class='name'>{{ subform.member.data }}
+    <td class='name'>{{ subform.member_name.data }}
       <div>
         {% if ppoc %}
           <span class='you'>PPoC</span>
         {% endif %}
-        {% if subform.user_id.data == user.id %}
+        {% if subform.member_id.data == current_member_id %}
           <span class='you'>(<span class='green'>you</span>)</span>
         {% endif %}
       </div>