UI polish and signed-tx colour fix (v0.3.3)

Fix and refine the BAL plugin GUI without changing business logic:

core/will.py: restore the PUSHED requirement in needs_server_check so a
signed-but-not-broadcast will is no longer server-queried and therefore
stays blue (COMPLETE) instead of turning red (CHECK_FAIL). This matches the
original Gitea check() condition.

gui/qt/widgets.py: WillSettingsWidget vertical layout now caps every row to
the widest date-row width and left-aligns them; the leading icons keep their
original HelpButton width.

gui/qt/lists.py + gui/qt/common.py: the wizard toolbar button now shows a
28x28 icon plus a bold 'Create your will' caption (QSize imported).

gui/qt/dialogs.py (BalBuildWillDialog):
- closing summary row labelled 'All done: Ok' with a blank separator above it;
- 'checking variables' capitalised to 'Checking variables' (redundant trailing
  colon dropped);
- final auto-closing countdown replaced by an explicit right-aligned 'Close'
  button; intermediate technical pauses kept; next-steps popup preserved.

gui/qt/window.py + core/plugin_base.py: guide show_message on build, and
sync_hide_filters() in update_all so hide flags refresh immediately.

tests: test_needs_server_check updated; added offscreen preview helpers.
Version bumped to 0.3.3. 186 tests pass; ruff clean (baseline only).

bal/gui/qt/common.py

@@ -49,8 +49,8 @@ from electrum.transaction import SerializationError, Transaction, tx_from_any
 from electrum.util import (DECIMAL_POINT, FileExportFailed, UserCancelled,
                            decimal_point_to_base_unit_name, read_json_file,
                            write_json_file)
-from PyQt6.QtCore import (QDateTime, QModelIndex, QPersistentModelIndex, Qt,
-                          QTimer, pyqtSignal)
+from PyQt6.QtCore import (QDateTime, QModelIndex, QPersistentModelIndex, QSize,
+                          Qt, QTimer, pyqtSignal)
 from PyQt6.QtGui import (QColor, QPainter, QPalette, QStandardItem,
                          QStandardItemModel)
 from PyQt6.QtWidgets import (QAbstractItemView, QAbstractSpinBox, QCheckBox,