Issue:
fix(users): Accepting invite for org_admins

Currently, when email feature flag is enabled and invite a org_admin, it throws error saying `InvalidRoleId`.

When we try to accept invite for `org_admin`s, it again throws `InvalidRoleId`.

This should not be the case, error should not be throws and invite should be accepted.

Resolution:
<think>
PR Context:
- Title: fix(users): Allow accepting invites for `org_admin`s
- Merged: 2024-10-08T11:43:23Z
- Files changed: 6 files
- Commits: 4 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Currently accepting invites for org_admin will not work. This PR fixes it.

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/envir
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(users): Allow accepting invites for `org_admin`s (#6253)
Files to modify:


**crates/diesel_models/src/query/user_role.rs**
  Modify existing code

**crates/router/src/core/user.rs**
  Modify existing code

**crates/router/src/core/user_role.rs**
  Modify existing code

**crates/router/src/db/kafka_store.rs**
  Modify existing code

**crates/router/src/db/user_role.rs**
  Modify existing code

**crates/router/src/utils/user_role.rs**
  Modify existing code