[FEATURE] Use proxy exclusion instead of a separate proxied client

### Feature Description

Currently we provide the option for proxying all external requests made to Connectors. We also use reqwest clients to make API calls to basilisk/locker or other utilities.

Recently we started reusing the `reqwest::Client` (via once_cell) for performance reasons
Our current approach involves maintaining 2 clients:
- Proxied Client for any requests going outside our system
- Non-Proxied client for internal services

Currently we need to maintain a list of the services that should bypass proxy & choose a client accordingly. This adds a bit of a boilerplate whenever we try to make requests.


### Possible Implementation

Expected behavior:

Instead we want to push this behavior down to the reqwest library…
we believe the [no_proxy](https://docs.rs/reqwest/latest/reqwest/struct.Proxy.html#method.no_proxy) function should help us avoid this maintenance.

We would ideally accept a list of `proxy_bypass_urls` as part of our config which would then be used to create a single `reqwest::Client`  which can be used for internal + external services

### Have you spent some time to check if this feature request has been raised before?

- [X] I checked and didn't find similar issue

### Have you read the Contributing Guidelines?

- [X] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

No, I don't have time to work on this right now
<think>
PR Context:
- Title: refactor(proxy): specify hosts for proxy exclusion instead of complete URLs
- Merged: 2025-01-15T13:04:48Z
- Files changed: 10 files
- Commits: 3 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [x] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->

This PR refactors the logic for excluding specific HTTP / HTTPS traffic from being proxied via the outgoing proxy. Specifically, the changes included are:

1. We no longer need two clients (a proxied client and a non-proxied client), we ca
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** refactor(proxy): specify hosts for proxy exclusion instead of complete URLs (#6957)
Files to modify:


**crates/common_enums/src/enums.rs**
  Modify existing code

**crates/router/src/bin/scheduler.rs**
  Modify existing code

**crates/router/src/configs/defaults.rs**
  Modify existing code

**crates/router/src/configs/settings.rs**
  Modify existing code

**crates/router/src/lib.rs**
  Modify existing code

**crates/router/src/services/api.rs**
  Modify existing code

**crates/router/src/services/api/client.rs**
  Remove:
    - function: pub::proxy_bypass_urls

**crates/router/src/services/openidconnect.rs**
  Modify existing code
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