Add UpdatePayload and DeleteRequest to arcticdb. import path (#2664)

#### Reference Issues/PRs
<!--Example: Fixes #1234. See also #3456.-->

#### What does this implement or fix?
* Moved `UpdatePayload` and `DeleteRequest` to `arcticdb` import. 
* Updated the docs so that `UpdatePayload` and `DeleteRequest` are
clickable
* Added docstrings to `UpdatePayload`

Proof
* Now showing `arcticdb.` import on hover
<img width="1243" height="563" alt="image"
src="https://github.com/user-attachments/assets/ea5dc467-5ba9-4f53-a16c-a81f89239a6d"
/>


* Clicking it shows the docstrings for the structure
Same for DeleteRequest

Author: ognyanstoimenov

docs/mkdocs/docs/api/library_types.md

@@ -4,6 +4,8 @@
 
 ::: arcticdb.ReadRequest
 
+::: arcticdb.DeleteRequest
+
 ::: arcticdb.version_store.library.SymbolDescription
 
 ::: arcticdb.version_store.library.SymbolVersion
@@ -15,3 +17,8 @@
 ::: arcticdb.version_store.library.VersionInfo
 
 ::: arcticdb.WritePayload
+
+::: arcticdb.UpdatePayload
+
+::: arcticdb.WriteMetadataPayload
+

python/arcticdb/__init__.py

@@ -14,8 +14,10 @@
 from arcticdb_ext.exceptions import ErrorCode, ErrorCategory
 from arcticdb.version_store.library import (
     WritePayload,
+    UpdatePayload,
     ReadInfoRequest,
     ReadRequest,
+    DeleteRequest,
     col,
     LazyDataFrame,
     LazyDataFrameCollection,

python/arcticdb/version_store/library.py

@@ -347,13 +347,39 @@ def __repr__(self):
 
 
 class UpdatePayload:
+    """
+    UpdatePayload is designed to enable batching of multiple operations with an API that mirrors the singular
+    ``update`` API.
+
+    Construction of ``UpdatePayload`` objects is only required for batch update operations.
+
+    One instance of ``UpdatePayload`` refers to one unit that can be written through to ArcticDB.
+
+    """
+
     def __init__(
         self,
         symbol: str,
         data: NormalizableType,
         metadata: Any = None,
         date_range: Optional[Tuple[Optional[Timestamp], Optional[Timestamp]]] = None,
     ):
+        """
+        Constructor.
+
+        Parameters
+        ----------
+        symbol : str
+            Symbol name. Limited to 255 characters. The following characters are not supported in symbols:
+            ``"*", "&", "<", ">"``
+        data : NormalizableType
+            Time-indexed data to use for the update.
+        metadata : Any, default=None
+            Optional metadata to persist along with the new symbol version.
+        date_range : Optional[Tuple[Optional[Timestamp], Optional[Timestamp]]], default=None
+            Restricts the update to the specified range in the stored data. Leaving either bound as ``None`` leaves that
+            side of the range open-ended.
+        """
         self.symbol = symbol
         self.data = data
         self.metadata = metadata
@@ -1420,7 +1446,7 @@ def update_batch(
         Parameters
         ----------
         update_payloads: List[UpdatePayload]
-            List `arcticdb.library.UpdatePayload`. Each element of the list describes an update operation for a
+            List of `UpdatePayload`. Each element of the list describes an update operation for a
             particular symbol. Providing the symbol name, data, etc. The same symbol should not appear twice in this
             list.
         prune_previous_versions: bool, default=False