Refactor: rename rmSpace to remove_redundant_spaces (#10796)

### What problem does this PR solve?

- rename rmSpace to remove_redundant_spaces
- move clean_markdown_block to common module
- add unit tests for remove_redundant_spaces and clean_markdown_block

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

test/unit_test/common/test_float_utils.py

@@ -0,0 +1,88 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+import math
+from common.float_utils import get_float
+
+class TestGetFloat:
+
+    def test_valid_float_string(self):
+        """Test conversion of valid float strings"""
+        assert get_float("3.14") == 3.14
+        assert get_float("-2.5") == -2.5
+        assert get_float("0.0") == 0.0
+        assert get_float("123.456") == 123.456
+
+    def test_valid_integer_string(self):
+        """Test conversion of valid integer strings"""
+        assert get_float("42") == 42.0
+        assert get_float("-100") == -100.0
+        assert get_float("0") == 0.0
+
+    def test_valid_numbers(self):
+        """Test conversion of actual number types"""
+        assert get_float(3.14) == 3.14
+        assert get_float(-2.5) == -2.5
+        assert get_float(42) == 42.0
+        assert get_float(0) == 0.0
+
+    def test_none_input(self):
+        """Test handling of None input"""
+        result = get_float(None)
+        assert math.isinf(result)
+        assert result < 0  # Should be negative infinity
+
+    def test_invalid_strings(self):
+        """Test handling of invalid string inputs"""
+        result = get_float("invalid")
+        assert math.isinf(result)
+        assert result < 0
+
+        result = get_float("12.34.56")
+        assert math.isinf(result)
+        assert result < 0
+
+        result = get_float("")
+        assert math.isinf(result)
+        assert result < 0
+
+    def test_boolean_input(self):
+        """Test conversion of boolean values"""
+        assert get_float(True) == 1.0
+        assert get_float(False) == 0.0
+
+    def test_special_float_strings(self):
+        """Test handling of special float strings"""
+        assert get_float("inf") == float('inf')
+        assert get_float("-inf") == float('-inf')
+
+        # NaN should return -inf according to our function's design
+        result = get_float("nan")
+        assert math.isnan(result)
+
+    def test_very_large_numbers(self):
+        """Test very large number strings"""
+        assert get_float("1e308") == 1e308
+        # This will become inf in Python, but let's test it
+        large_result = get_float("1e500")
+        assert math.isinf(large_result)
+
+    def test_whitespace_strings(self):
+        """Test strings with whitespace"""
+        assert get_float("  3.14  ") == 3.14
+        result = get_float("  invalid  ")
+        assert math.isinf(result)
+        assert result < 0