Resolve CE/EE duplication in `invite_modal_base.vue`
Description
Over in !79644 (merged) we needed to introduce an EE only feature to a CE invite_modal_base.vue
component. As a result, the entire CE component was duplicated, introducing a bit of technical debt and risk of EE diverging from CE
From the EE guideline
Since the implementation of GitLab CE features to work with unlicensed EE instance GitLab Enterprise Edition should work like GitLab Community Edition when no license is active. So EE features always should be guarded by project.feature_available? or group.licensed_feature_available? (or License.feature_available? if it is a system-wide feature).
Proposal
Let's update ee/.../invite_modal_base.vue
to compose the CE one. Most of the logic should exist in CE and the EE component should include only the parts which are needed for EE.