Add Site Roles to Users (and User Groups) function in Site Memberships portlet

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X EE, Master
• Fix Version/s: 7.0.0 DXP FP15, 7.0.3 CE GA4, 7.0.0 DXP SP4, 7.0.X EE, 7.1.X, Master
• Component/s: Sites Administration
• Labels:
  • ee-ts
  • liferay-digital-enterprise-70-sp4
  • liferay-fixpack-de-15-7010
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/48557

Description
On 7.0, we can't see the users that are assigned to a specific site role through the GUI. Compare this to 6.2's behavior where we were able to view site role assignments through the GUI:
1. Click on Admin > Site Administration
2. Users > Add Site Roles to > Users > select a Site role
Please refer to 6.2 behavior.

Actual Behavior
The way to assign roles has changed on 7.0. In DXP, you have to select the user individually and assign a site role. There is no way to view the current/available all users that are assigned to the site role. It should be a big loss in functionality, we can't assign or unassign users to the specific Site Roles. However, if we look at organization role, this presents the same behavior as 6.2.

Expected Behavior
Site Role assignment should be consistent with 6.2. Add the function back to 7.0