Remove `ANNErrorKind` from `ANNError`, removing all the old `log_`
constructors and slimming the constructors to `new`, `message`, and
`context.

Since `diskann-disk` leans pretty heavily to using the kinds in its
tests, a new `diskann_disk::error::Error` type is introduces along with
a `diskann_error!` macro to largely preserve test structure and error
kind tagging. See the review notes for more information.

# Why
The error kind enum is largely unused at this point, is not applied
consistently, and complicates the API for `ANNError`. It's time to
remove it and bring the size of `ANNError` down to 8-bytes.

# Review Order

**`diskann`**
- `error/ann_error.rs`: Removal of the `ANNErrorKind` enum and the
`log_*` style constructors. As a bonus, I added a `convert_error!` macro
(happy to bike-shed) to stamp out simple conversion cases while
preserving `track_caller`.

The rest of the changes in `diskann` are removing the `ANNErrorKind` and
switching over to the `convert_error!` macro.


**`diskann-tools`/`diskann-providers`/`diskann-garnet`/`diskann-label-filter`/`diskann-bftree`/`diskann-benchmark-core`/`diskann-benchmark`**
These mainly consist of updating the constructors and conversions. Note
that where possible (and easily achievable), I use the [moving form of
`lazy_format!`](https://github.com/microsoft/DiskANN/blob/e197b434912f7b13c64f1d89785f58ba7d5de22d/diskann-utils/src/lazystring.rs#L56-L74)
to avoid eager string formatting.

**`diskann-disk`
This is the perhaps a more controversial change. `diskann-disk`'s tests
lean heavily into the error kind and `log*` style constructors. I tried
to preserve as much of the original behavior as possible by introducing
an error type `diskann_disk::error::Error` consisting of a
string-message an a `diskann_disk::error::ErrorKind` enum. A macro
`diskann_disk::error::diskann_error!` helps embed this new `Error`
inside of an `ANNError`. While this goes against the ethos of "don't
have crate level errors", here is my rationale:

* By using the `log_*` constructors, `diskann_disk`'s error types are
already fundamentally tagged string messages.
* Introducing an `Error` type means we can still check the `Kind` enum
by downcasting the resulting `ANNError` down to the original `Error`.
* Since the existing `diskann_disk` code is already doing eager string
formatting/allocating at its error construction callsites, this isn't
introduction a regression. Indeed, I've added some tricks to avoid
allocating when constructing `diskann_disk::error::Error` from string
literals, which is fairly common.
* Moving the kind tag to `diskann_disk` allows the disk index to add
error types without disrupting `ANNError`.

# Alternatives
* This is an alternative to #1278 that I was unfortunately working on in
parallel.
* One functionality we lost with this is the ability to recover the
inner error types from the tag. Theoretically, the tag type could be
used by third-party crates to guide the proper type for a downcast. In
practice, no one is doing this.

---------

Co-authored-by: Mark Hildebrand <mhildebrand@microsoft.com>