Issue:
feat: get specific user role details api

Currently frontend is using the user list api to get the details of the users in a particular merchant account.

If somebody is in a user details page and refreshes, FE will again call list api to get the details as there is no api to get the details of a specific user.

Resolution:
<think>
PR Context:
- Title: feat(users): Add new API get the user and role details of specific user
- Merged: 2024-03-07T06:37:39Z
- Files changed: 7 files
- Commits: 3 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [x] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Currently there is no way to get the details of user and their role directly. This API solves it by taking the email of the user and returns the details.

### Additional Changes

- [x] This PR modifies the API contract
- [ ] This PR modif
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** feat(users): Add new API get the user and role details of specific user (#3988)
Files to modify:


**crates/api_models/src/events/user.rs**
  Modify existing code

**crates/api_models/src/user.rs**
  Remove:
    - struct: pub::GetUsersResponse
  Add:
    - struct: pub::ListUsersResponse
    - struct: pub::GetUserDetailsRequest
    - struct: pub::GetUserDetailsResponse

**crates/router/src/core/user.rs**
  Add:
    - function: pub::get_user_details_in_merchant_account

**crates/router/src/routes/app.rs**
  Modify existing code

**crates/router/src/routes/lock_utils.rs**
  Modify existing code

**crates/router/src/routes/user.rs**
  Add:
    - function: pub::get_user_role_details

**crates/router_env/src/logger/types.rs**
  Modify existing code