fix: shadows in insertion markers being displayed as shadows

[BeksOmega]

The basics

• I validated my changes

The details

Resolves

Fixes #7466

Proposed Changes

Makes it so that children of insertion markers are also set as insertion markers

Reason for Changes

You can set shadow blocks programmatically, but they weren't previously being set as insertion markers.

Test Coverage

Tested with the following two block definitions. The first sets the shadow in the init method, the second sets the shadow in the loadExtraState method.

      Blockly.Blocks['test'] = {
        init: function () {
          this.appendValueInput('test').connection.setShadowState({
            'type': 'math_number',
          });
          this.setPreviousStatement(true);
        },
      };

      Blockly.Blocks['test2'] = {
        init: function () {
          this.appendValueInput('test');
          this.setPreviousStatement(true);
        },

        loadExtraState: function () {
          this.getInput('test').connection.setShadowState({
            'type': 'math_number',
          });
        },

        saveExtraState: function () {
          return true;
        },
      };

Screen.recording.2023-10-23.3.06.57.PM.webm

Added unit tests.

Documentation

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Additional Information

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