Issue:
Todo redis interface

## Type of Change
<!-- Put an `x` in the boxes that apply -->
- [x] Enhancement

## Description
This PR is a part of greater refactoring which aims on removing `// TODO: ...` & `// FIXME: ..` from the entire codebase.
The objective of this PR is to fix `xgroup_create` by adding a guard or some specific `RedisEntryId` while also adding unit tests for the same. It also adds crate documentation for the `redis_interface` crate
<!-- Describe your changes in detail -->


### Additional Changes

- [ ] 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
The codebase wide initiative in fixing existing problems, `TODO:`s and `FIXME:`s while also adding documentations.
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can focus on the implementation (unless its an obvious bug or documentation fix
that will have little conversation).
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## How did you test it?
unit-tests included
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Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
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## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed submitted code
- [x] I added unit tests for my changes where possible

Resolution:
<think>
PR Context:
- Title: fix(router_env): resolve/remove `FIXME`'s and redundent files
- Merged: 2022-12-19T10:11:26Z
- Files changed: 7 files
- Commits: 5 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Enhancement

## Description
This PR is regarding the `FIXME`'s and `TODO`'s resolution for the crate `router_env`
<!-- Describe your changes in detail -->


### Additional Changes

- [ ] 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
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(router_env): resolve/remove `FIXME`'s and redundent files (#168)
Files to modify:


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

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

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

**crates/router_env/src/logger/setup.rs**
  Remove:
    - function: private::on_event
    - struct: pub::DebugLayer
    - impl: impl Layer<S> for DebugLayer