feat(python): Hybrid search & Reranker API (#824)

based on https://github.com/lancedb/lancedb/pull/713
- The Reranker api can be plugged into vector only or fts only search
but this PR doesn't do that (see example -
https://txt.cohere.com/rerank/)


### Default reranker -- `LinearCombinationReranker(weight=0.7,
fill=1.0)`

```
table.search("hello", query_type="hybrid").rerank(normalize="score").to_pandas()
```
### Available rerankers
LinearCombinationReranker
```
from lancedb.rerankers import LinearCombinationReranker

# Same as default 
table.search("hello", query_type="hybrid").rerank(
                                      normalize="score", 
                                      reranker=LinearCombinationReranker()
                                     ).to_pandas()

# with custom params
reranker = LinearCombinationReranker(weight=0.3, fill=1.0)
table.search("hello", query_type="hybrid").rerank(
                                      normalize="score", 
                                      reranker=reranker
                                     ).to_pandas()
```

Cohere Reranker
```
from lancedb.rerankers import CohereReranker

# default model.. English and multi-lingual supported. See docstring for available custom params
table.search("hello", query_type="hybrid").rerank(
                                      normalize="rank",  # score or rank
                                      reranker=CohereReranker()
                                     ).to_pandas()

```

CrossEncoderReranker

```
from lancedb.rerankers import CrossEncoderReranker

table.search("hello", query_type="hybrid").rerank(
                                      normalize="rank", 
                                      reranker=CrossEncoderReranker()
                                     ).to_pandas()

```

## Using custom Reranker
```
from lancedb.reranker import Reranker

class CustomReranker(Reranker):
    def rerank_hybrid(self, vector_result, fts_result):
           combined_res = self.merge_results(vector_results, fts_results) # or use custom combination logic
           # Custom rerank logic here
           
           return combined_res
```

- [x] Expand testing
- [x] Make sure usage makes sense
- [x] Run simple benchmarks for correctness (Seeing weird result from
cohere reranker in the toy example)
- Support diverse rerankers by default:
- [x] Cross encoding
- [x] Cohere
- [x] Reciprocal Rank Fusion

---------

Co-authored-by: Chang She <759245+changhiskhan@users.noreply.github.com>
Co-authored-by: Prashanth Rao <35005448+prrao87@users.noreply.github.com>

python/lancedb/table.py

@@ -16,7 +16,7 @@ from __future__ import annotations
 import inspect
 from abc import ABC, abstractmethod
 from functools import cached_property
-from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Union
+from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Tuple, Union
 
 import lance
 import numpy as np
@@ -33,8 +33,7 @@ from .query import LanceQueryBuilder, Query
 from .util import (
     fs_from_uri,
     join_uri,
-    safe_import_pandas,
-    safe_import_polars,
+    safe_import,
     value_to_sql,
 )
 from .utils.events import register_event
@@ -48,8 +47,8 @@ if TYPE_CHECKING:
     from .db import LanceDBConnection
 
 
-pd = safe_import_pandas()
-pl = safe_import_polars()
+pd = safe_import("pandas")
+pl = safe_import("polars")
 
 
 def _sanitize_data(
@@ -338,7 +337,7 @@ class Table(ABC):
     @abstractmethod
     def search(
         self,
-        query: Optional[Union[VEC, str, "PIL.Image.Image"]] = None,
+        query: Optional[Union[VEC, str, "PIL.Image.Image", Tuple]] = None,
         vector_column_name: str = VECTOR_COLUMN_NAME,
         query_type: str = "auto",
     ) -> LanceQueryBuilder:
@@ -924,7 +923,7 @@ class LanceTable(Table):
 
     def search(
         self,
-        query: Optional[Union[VEC, str, "PIL.Image.Image"]] = None,
+        query: Optional[Union[VEC, str, "PIL.Image.Image", Tuple]] = None,
         vector_column_name: str = VECTOR_COLUMN_NAME,
         query_type: str = "auto",
     ) -> LanceQueryBuilder:
@@ -1194,6 +1193,7 @@ class LanceTable(Table):
                 "nprobes": query.nprobes,
                 "refine_factor": query.refine_factor,
             },
+            with_row_id=query.with_row_id,
         )
 
     def cleanup_old_versions(