Add size constraints to SearchBar and improve docs

Introduces `bar_size_constraints` to the SearchBar control and theme, allowing optional size constraints. Also updates and expands documentation for SearchBar properties and SearchBarTheme overrides for better clarity and developer guidance.

Author: InesaFitsner

packages/flet/lib/src/controls/search_bar.dart

@@ -208,6 +208,8 @@ class _SearchBarControlState extends State<SearchBarControl> {
             shape:
                 widget.control.getWidgetStateOutlinedBorder("bar_shape", theme),
             padding: widget.control.getWidgetStatePadding("bar_padding"),
+            constraints:
+                widget.control.getBoxConstraints("bar_size_constraints"),
             textStyle:
                 widget.control.getWidgetStateTextStyle("bar_text_style", theme),
             hintStyle: widget.control

sdk/python/packages/flet/src/flet/controls/material/search_bar.py

@@ -78,37 +78,44 @@ class SearchBar(ConstrainedControl):
 
     bar_shadow_color: Optional[ControlStateValue[ColorValue]] = None
     """
-    TBD
+    The shadow color of the search bar.
     """
 
     bar_elevation: Optional[ControlStateValue[Optional[Number]]] = None
     """
-    TBD
+    The elevation of the search bar.
     """
 
     bar_border_side: Optional[ControlStateValue[BorderSide]] = None
     """
-    TBD
+    The color and weight of the search bar's outline.
+
+    This value is combined with [`SearchBar.bar_shape`][flet.SearchBar.bar_shape] to
+    create a shape decorated with an outline.
     """
 
     bar_shape: Optional[ControlStateValue[OutlinedBorder]] = None
     """
-    TBD
+    The shape of the search bar.
+
+    This shape is combined with
+    [`SearchBar.bar_border_side`][flet.SearchBar.bar_border_side] to create a shape
+    decorated with an outline.
     """
 
     bar_text_style: Optional[ControlStateValue[TextStyle]] = None
     """
-    TBD
+    The style to use for the text being edited.
     """
 
     bar_hint_text_style: Optional[ControlStateValue[TextStyle]] = None
     """
-    TBD
+    The style to use for the [`SearchBar.bar_hint_text`][flet.SearchBar.bar_hint_text].
     """
 
     bar_padding: Optional[ControlStateValue[PaddingValue]] = None
     """
-    TBD
+    The padding between the search bar's boundary and its contents.
     """
 
     bar_scroll_padding: PaddingValue = 20
@@ -120,6 +127,11 @@ class SearchBar(ConstrainedControl):
     distance from the Scrollable edges.
     """
 
+    bar_size_constraints: Optional[BoxConstraints] = None
+    """
+    Optional size constraints for the search bar.
+    """
+
     view_leading: Optional[Control] = None
     """
     A `Control` to display before the text input field when the search view is open.

sdk/python/packages/flet/src/flet/controls/theme.py

@@ -2875,14 +2875,67 @@ class SearchBarTheme:
     """
 
     shadow_color: Optional[ControlStateValue[ColorValue]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_shadow_color`][flet.SearchBar.bar_shadow_color] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     overlay_color: Optional[ControlStateValue[ColorValue]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_overlay_color`][flet.SearchBar.bar_overlay_color] in all
+    descendant [`SearchBar`][flet.SearchBar] controls.
+    """
+
     elevation: Optional[ControlStateValue[Optional[Number]]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_elevation`][flet.SearchBar.bar_elevation] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     text_style: Optional[ControlStateValue[TextStyle]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_text_style`][flet.SearchBar.bar_text_style] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     hint_style: Optional[ControlStateValue[TextStyle]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_hint_style`][flet.SearchBar.bar_hint_style] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     shape: Optional[ControlStateValue[OutlinedBorder]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_shape`][flet.SearchBar.bar_shape] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     padding: Optional[ControlStateValue[PaddingValue]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_padding`][flet.SearchBar.bar_padding] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     size_constraints: Optional[BoxConstraints] = None
+    """
+    Overrides the default value of
+    [`SearchBar.size_constraints`][flet.SearchBar.size_constraints] in all descendant
+    [`SearchBar`][flet.SearchBar] controls.
+    """
+
     border_side: Optional[ControlStateValue[BorderSide]] = None
+    """
+    Overrides the default value of
+    [`SearchBar.bar_border_side`][flet.SearchBar.bar_border_side] in all
+    descendant [`SearchBar`][flet.SearchBar] controls.
+    """
 
 
 @dataclass