Fix un-init base path when switch AnimationNode in BlendSpace2D

[xuhuisheng]

• Fixes: Errors when switching animations while in Capture blend mode in BlendSpace1D and BlendSpace2D #112053
• Related: Fix missing process_state error in blend spaces. #104018
• Related: No difference between Discrete and Capture blend modes in BlendSpace2D #111893
• Forum: https://forum.godotengine.org/t/possible-permanence-of-issue-104018/106174

Issue Description

When we move position in BlenderSpace2D with capture, it will try to copy backward property from current_animation to new_animation when switch animation.

E 0:00:04:817   set_parameter: Condition "!process_state->tree->property_parent_map.has(node_state.base_path)" is true.
  <Origem C++>  scene/animation/animation_tree.cpp:84 @ set_parameter()

That caused by new_animation hasnot init base_path.

Solution

This patch inited base_path for new_animation.

[PavielKraskouski]

Errors also occur in BlendSpace1D. This needs to be fixed as well.

[PavielKraskouski]

Opened #112053 for this PR.

[xuhuisheng]

@PavielKraskouski

Thanks for the reminder. Added 'AnimationBlendSpace1D' as well.

[TokageItLab]

I wonder if setting node_state_base_path in the subclass is the correct approach.
The issue will probably be resolved by #112308 guarantee of process_state, then this PR is superseded with that.