## Problem

Need to update generated code for the upcoming 2024-07 API release.

## Solution

This PR closely follows the approach used in the python and typescript
repositories.

- I create a new `codegen` directory to act as the home for everything
codegen related. Inside this directory there are several things:
  - Git submodule of our apis repo
- A `build-oas.sh` script which does everything to generate the code off
the spec

The script does the following:
- Pulls in the latest from the apis repo
- Builds the api repo to produce versioned spec files
- Generates java code off the spec file.
- Copies files into their respective places in `src/`

Run the script like this, passing api version number as a positional
argument:

```sh
./codegen/build-oas.sh 2024-07
```

## Non-generated changes

The updated spec produced slightly different generated code than in the
past. In order for the project to compile, I had to make some
adjustments:

- Options for metric type are now part of the `IndexModel` class instead
of a standalone metric object, requiring a small refactor along the
lines of `IndexMetric.COSINE.toString()` to
`IndexModel.MetricEnum.COSINE.toString()` and similar for other metric
types.
- The name and organization of create index spec objects has changed.
Now you use:
  - `IndexSpec` instead of `CreateInexRequestSpec`.
  - `PodSpec` instead of `CreateIndexRequestSpecPod`
- `PodSpecMetadataConfig` instead of
`CreateIndexRequestSpecPodMetadataConfig`

## Type of Change

- [x] None of the above: Update generated core, adjust usage for new
generated classes

## Test Plan

Code builds and tests pass

## Problem

Add support for deletion protection.

## Solution

Generated code using the following commands: 
```
git submodule init && git submodule update
./codegen/build-oas.sh 2024-07
```
Next, as a part of this PR, I have: 
1. Added deletionProtection enum as an argument to createPodsIndex() and
createServerlessIndex()
2. Renamed configureIndex() to configurePodsIndex() and added
deletionProtection enum as an argument.
3. Added configureServerlessIndex() that accepts deletionProtection enum
only.


## Type of Change

- [X] New feature (non-breaking change which adds functionality)

## Test Plan

Added integration tests