Getting back toolbar on left (if set to top position) in 0.8.4?

まず、提供された再現手順を ipympl 0.8.4 と記載されている Jupyter および ipywidgets のバージョンで実行し、その後、ツールバーとウィジェットのレイアウトの挙動を以前の例と比較します。完了の条件は、ツールバーを左上に配置し直し、figure を Hello ウィジェットと World ウィジェットの間に維持し、ハンバーガーコントロールを復元できるかどうかを確認することです。

Describe the issue

In an earlier version of ipympl (unfortunately, haven't recorded which), if I chose the positioning of the toolbar on top, it was automatically placed on the left; I have a partial record of that here - https://stackoverflow.com/questions/69106967/jupyter-matplotlib-widget-place-toolbar-horizontally-over-plot

However, I made an update recently, and it turns out, the hacks that I have documented previously, do not work anymore - also because now the default for fig.canvas.toolbar_visible seems to be fade-in-fade-out (apparently, when I documented above hacks, the default was visible).

So now, if you run the last code snippet in the answer of the linked SO post above (only thing I added was version printout):

%matplotlib widget
import ipympl; print("ipympl version {}".format(ipympl.__version__))

import matplotlib.pyplot as plt
from ipywidgets import widgets, Layout
from IPython.display import display, HTML

out_widget_plot = widgets.Output()
with out_widget_plot:
    with plt.style.context("default"): # ggplot
        fig, (ax1) = plt.subplots(1, 1)

fig.suptitle('test title', fontsize=10) 
tline = ax1.plot([0,1,2], [10,20,30])
fig.tight_layout()
#fig.canvas.toolbar.button_style = 'info' # test: ok, works (but don't need it here)
#fig.canvas.toolbar.orientation = 'horizontal' # no error, but no effect either
fig.canvas.toolbar_position = 'top' # this also switches the orientation to horizontal, too
fig.canvas.header_visible = False # Gets rid of "Figure 1" on top

# the below CSS style override in Jupyter, allows the div that hosts the Matplotlib toolbar, to be placed "on top" of the div that hosts the plot:
# widget-label does the same, but for the bottom "x/y" indicator (which is why its position needs to also be controlled with margin)
sthtml = """
<style>
.jupyter-matplotlib-toolbar {
    overflow: visible;
    position: absolute;
    z-index: 1000;
}
.widget-label {
    color: var(--jp-widgets-label-color);
    font-size: var(--jp-widgets-font-size);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    line-height: var(--jp-widgets-inline-height);
    z-index: 1000;
    margin-top: -41px;
    margin-left: 58px;
}
</style>
"""

the_ui = widgets.VBox([ widgets.HTML(sthtml), widgets.HTML("<b>Hello</b>"), out_widget_plot, widgets.HTML("<b>World</b>"),])
display(the_ui)

... you at first do not get any toolbar menu (because due to the fade-in-fade-out, the menu is not shown, if the mouse cursor is not over the plot widget), then when you mouseover, you get the toolbar to the right (and there is no "hamburger" icon at first, that used to collapse/expand the rest of the toolbar; and the plot figure rendered after the two HTML "labels", "Hello" and "World"):

... whereas the same code earlier showed a toolbar on the left (and there is "hamburger" icon at first, that used to collapse/expand the rest of the toolbar, shown; and the plot being rendered between the two HTML "labels") :

Note also that now, the figure plot widget is not shown anymore between the "Hello" and the "World" labels - whereas previously it was (which was the intention).

Is there any way I can get the old behavior back, so I can place the toolbar on the top left, and have the figure shown between other widgets (and possibly get the "hamburger" expand/collapse button back)?

Versions

3.8.10 (default, Sep 28 2021, 16:10:42) 
[GCC 9.3.0]
ipympl version: 0.8.4
Selected Jupyter core packages...
IPython          : 7.30.1
ipykernel        : 6.6.0
ipywidgets       : 7.6.5
jupyter_client   : 7.1.0
jupyter_core     : 4.9.1
jupyter_server   : 1.13.1
jupyterlab       : not installed
nbclient         : 0.5.9
nbconvert        : 6.3.0
nbformat         : 5.1.3
notebook         : 6.4.6
qtconsole        : 5.2.2
traitlets        : 5.1.1
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      - Validating: OK
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      ipyvolume/extension  enabled 
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      jupyter-datawidgets/extension  enabled 
      - Validating: OK
      jupyter-leaflet/extension  enabled 
      - Validating: OK
      jupyter-matplotlib/extension  enabled 
      - Validating: OK
      jupyter-threejs/extension  enabled 
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      jupyter-webrtc/extension  enabled 
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    tree section
      nbextensions_configurator/tree_tab/main  enabled 
      - Validating: problems found:
        - require?  X nbextensions_configurator/tree_tab/main
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