fix: fix map get return double nested nullable

[ariesdevil]

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Summary

for this query:

CREATE OR REPLACE TABLE t1(tags Map(String, String)) Engine = Fuse

statement ok
INSERT INTO t1 VALUES ({'region':'sg', 'az': '1'}),({'region':'sg', 'az': '2'}), ({'region':'hk', 'az': '1'}),({'region':'hk', 'az': '2'})

query I
SELECT to_int32(tags['az']) AS int_az FROM t1 WHERE tags['region'] = 'sg' ORDER BY int_az;

The tags[az] will call map#get with input data type MapType<GenericType<0>, GenericType<1>> and return data type NullableType<GenericType<1>>, however, if GenericType<1> is already a nullable type, this will return Nullable<Nullable<XXX>>.

When this return type pass to to_int32, the try_downcast_column().unwrap() will failed.

This PR add a new get function for map get that catch nullable value in map first.

• Fixes #[Link the issue here]

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[what-the-diff]

PR Summary

• Introduction of Updated "Get" Function
  This update includes a new version of the "get" function that can handle maps with values that may or may not exist (nullable values). This allows more flexibility when working with these types of data structures.

• Inclusion of Revised "Get" Function in Function List
  The new "get" function has also been incorporated into the existing list of available functions, making it conveniently available for use in future coding tasks.

• Modification of "Get" Function Test Cases
  The test cases specifically designed for the "get" function have been revised so they now use this new implementation. This ensures the updated function operates as expected.

• Addition of Test Cases for Operation on Table with Map Column
  New test cases have been introduced to check operations like inserting and querying on tables having a column of the map types. By ensuring diverse test environment, we are increasing the robustness and reliability of our application.

• Corrections in Map Column Table Creation Test Case
  An error identified in a test case that handles the creation of tables with a map column has been fixed, increasing overall testing accuracy and smoothness of operation in this scenario.

[ariesdevil]

The failed unit test may not related this PR, seems a flaky test:

Summary [ 190.527s] 1614 tests run: 1613 passed (2 slow), 1 failed, 9 skipped
        FAIL [   0.106s] databend-storages-common-index::it filters::bloom_filter::test_bloom_filter

[ariesdevil]

The failed unit test may not related this PR, seems a flaky test:

Summary [ 190.527s] 1614 tests run: 1613 passed (2 slow), 1 failed, 9 skipped
        FAIL [   0.106s] databend-storages-common-index::it filters::bloom_filter::test_bloom_filter

This actually related to this PR, fixed.