Evaluate usage of "sharing" and "invite" in groups and projects

Problem

Users can make use of the group sharing functionality to invite members to a group or project. In the documentation we talk about the group sharing functionality, but in the product we often use "invite" when prompting a user to share their group. This issue is to evaluate whether we can align on the language used around sharing to be clearer that it refers to the same functionality.

Exploration

Current screens

Description	Screen(s)
The group overview screen uses shared projects to describe which projects this group has been shared with
The project members page uses invite members and invite a group
The modal to invite a group to a project uses invite

Proposal

"Assign" or "assignment" are the typical words when it comes to user group management. See also gitlab-com/content-sites/handbook!14179 (comment 2582862639).

Implementation

• Decide on one terminology
• Generate issues to update wording in the product
• Update the documentation