Enable Shared IDP in OSP invite api

# Overview

## Explain the topic in 2 sentences
To improve user experience and sovereignty of customers onboarded through OSP, we plan to enable shared IdP as well.

## What's the benefit?
Companies onboarded through OSP will be able to invite their own employees with various user roles and see their own company name in Portal. Currently the OSP-onboardee has limited abilities compared to normally onboarding companies and this change will give them the same freedom.

## What are the Risks/Dependencies ?

No dependency
## Detailed explanation

### Current implementation
Current implementation lacks some key features needed to make sure the customers onboarded through OSP can truly own and manage their organization. Currently OSP invite companies via Managed IDP and hence invitee company can't add more user on their own .
### Proposed improvements
Addition of Shared IdP as option next to the existing solutions for Managed and Own IdP in OSP invite.
## Feature Team

### Contributor

- @dhiren-singh-007
- @Usmanfee
- @ybidois

### Committer

- @ntruchsess
- @Phil91
- @saadanzari

## User Stories

-
## Acceptance Criteria

- [ ] Acceptance Criteria 1

## Test Cases

Test cases will be developed in the User Stories by our QA @Sana

## Architectural Relevance

The following items are ensured (answer: yes) after this issue is implemented:

- [ ] This feature aligns with our current architectural guidelines
- **Data Sovereignty:** All data sharing activities across company boundaries follow the [Catena-X Regulatory Framework](https://catenax-ev.github.io/docs/next/regulatory-framework/governance-framework), in particular the [Data Exchange Governance](https://catenax-ev.github.io/docs/next/regulatory-framework/20000ft/data-exchange-governance), and the [Dataspace Protocol](https://docs.internationaldataspaces.org/dataspace-protocol/overview/readme) via a compliant Connector (like the [tractusx-edc](https://github.com/eclipse-tractusx/tractusx-edc) or similar, see [Connector KIT](https://eclipse-tractusx.github.io/docs-kits/next/category/connector-kit))
- [ ] [CX-0010 Business Partner Number](https://catenax-ev.github.io/docs/next/standards/CX-0010-BusinessPartnerNumber)
- [ ] [CX-0013 Identity of Member Companies](https://catenax-ev.github.io/docs/next/standards/CX-0013-IdentityOfMemberCompanies)
- [ ] [CX-0018 Data Space Connectivity (EDC)](https://catenax-ev.github.io/docs/next/standards/CX-0018-DataspaceConnectivity)
- [ ] [CX-0049 DID Document Schema](https://catenax-ev.github.io/docs/next/standards/CX-0049-DIDDocumentSchema)
- [ ] [CX-0050 Framework Agreement Credential](https://catenax-ev.github.io/docs/next/standards/CX-0050-FrameworkAgreementCredential)
- [ ] [CX-0149 Verified Company Identity](https://catenax-ev.github.io/docs/next/standards/CX-0149-Dataspaceidentityandidentification)
- **Interoperability:** Digital Twins are used (compliant to the [Digital Twin KIT](https://eclipse-tractusx.github.io/docs-kits/next/category/digital-twin-kit) and the [Industry Core KIT](https://eclipse-tractusx.github.io/docs-kits/next/category/industry-core-kit))
- [ ] [CX-0001 EDC Discovery API](https://catenax-ev.github.io/docs/next/standards/CX-0001-EDCDiscoveryAPI)
- [ ] [CX-0002 Digital Twins in Catena-X](https://catenax-ev.github.io/docs/next/standards/CX-0002-DigitalTwinsInCatenaX)
- [ ] [CX-0018 Data Space Connectivity (EDC)](https://catenax-ev.github.io/docs/next/standards/CX-0018-DataspaceConnectivity)
- **Data Format:**
- [ ] The data model is based on a [published Semantic Model](https://github.com/eclipse-tractusx/sldt-semantic-models)
- [ ] The impact on the overall system architecture has been assessed. The Feature does not require changes to the architecture or any existing standard? Please have a look here on the [overarching architecture](https://eclipse-tractusx.github.io/docs/tutorials/e2e/inform/architecture)
- [ ] Potential risks or conflicts with existing architecture has been assessed

**Justification:** _(Fill this out, if at least one of the checkboxes above cannot be ticked. Contact the Architecture Management Committee to get an approval for the justification)_

## Additional information

- [ ] I am aware that my request may not be developed if no developer can be found for it. I'll try to contribute a developer (bring your own developer)