Bug: bug(user_roles): Restrict updating user_roles to the same entity level



Currently update user role API allows updating a merchant level user role to profile level, which should not be possible.

This comes under upgrade/downgrade functionality, which is not available yet.

diff --git a/crates/router/src/core/user_role.rs b/crates/router/src/core/user_role.rs
index e10fa0eb81c..f2e9f758158 100644
--- a/crates/router/src/core/user_role.rs
+++ b/crates/router/src/core/user_role.rs
@@ -151,6 +151,14 @@ pub async fn update_user_role(
             ));
         }
 
+        if role_info.get_entity_type() != role_to_be_updated.get_entity_type() {
+            return Err(report!(UserErrors::InvalidRoleOperation)).attach_printable(format!(
+                "Upgrade and downgrade of roles is not allowed, user_entity_type = {} req_entity_type = {}",
+                role_to_be_updated.get_entity_type(),
+                role_info.get_entity_type(),
+            ));
+        }
+
         if updator_role.get_entity_type() < role_to_be_updated.get_entity_type() {
             return Err(report!(UserErrors::InvalidRoleOperation)).attach_printable(format!(
                 "Invalid operation, update requestor = {} cannot update target = {}",
@@ -216,6 +224,14 @@ pub async fn update_user_role(
             ));
         }
 
+        if role_info.get_entity_type() != role_to_be_updated.get_entity_type() {
+            return Err(report!(UserErrors::InvalidRoleOperation)).attach_printable(format!(
+                "Upgrade and downgrade of roles is not allowed, user_entity_type = {} req_entity_type = {}",
+                role_to_be_updated.get_entity_type(),
+                role_info.get_entity_type(),
+            ));
+        }
+
         if updator_role.get_entity_type() < role_to_be_updated.get_entity_type() {
             return Err(report!(UserErrors::InvalidRoleOperation)).attach_printable(format!(
                 "Invalid operation, update requestor = {} cannot update target = {}",

## 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 update user role API allows updating a merchant level user role to profile level, which should not be possible.

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!--
Provide links to the files with corresponding changes.

Following are the paths where you can find config files:
1. `config`
2. `crates/router/src/configs`
3. `loadtest/config`
-->


## Motivation and Context
<!--
Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.

If you don't have an issue, we'd recommend starting with one first so the PR
can focus on the implementation (unless it is an obvious bug or documentation fix
that will have little conversation).
-->
Closes #6222.

## How did you test it?
<!--
Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
-->
```curl
curl --location 'http://localhost:8080/user/user/update_role' \
--header 'Authorization: JWT' \
--data-raw '{
    "email": "merchant level user email",
    "role_id": "profile_admin"
}'
```
This call should throw the following error.
```json
{
    "error": {
        "type": "invalid_request",
        "message": "User Role Operation Not Supported",
        "code": "UR_23"
    }
}
```

## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible
