* Adjust map defaults and switch to BaseControl

Multiple map-related fixes and defaults:

- Example: set SafeArea expand=True in basic map example to allow full expansion.
- Tile layer: use BaseControl instead of LayoutControl when composing TileLayerControl.
- Map utils: change fadeIn start/reload opacities default to 0.0; set pinch_move_threshold default to 40.0; provide fallback durations for performLeapTriggerDuration and animationCurveReverseDuration; make cursor keyboard trigger nullable when trigger_keys is absent; set WMS tile layer defaults for format ('image/png') and version ('1.1.1').

These changes prevent null/undefined behavior and ensure sensible defaults for map interactions and tile rendering.

* fix: align Dart-side defaults with Python for props not sent when unchanged

- Dismissible: read "movement_duration"/"resize_duration" instead of "duration" for both
- Image: add default `false` for gapless_playback
- ExpansionTile: add default `true` for enable_feedback
- DataTable2: fix sort_arrow_animation_duration unit (microseconds → milliseconds)
- Geolocator: fix notification_set_ongoing default (true → false)
- SecureStorage: fix WebOptions db_name/public_key to use "Flet" prefix

* docs: add warning about matching Python↔Dart default values for extension developers