add argument to modify hover box position/direction

Right now developers can't modify the hover box position respective to the point the user is hovering. The hover box position is determined by:

• The numbers in the "transform=translate(valuex, valuey)" argument of the g element with className="hovertext": https://github.com/plotly/plotly.js/blob/master/src/components/fx/hover.js#L1200
• The shape specified in d in the path element (for the triangle orientation): https://github.com/plotly/plotly.js/issues/7278

https://github.com/user-attachments/assets/0634d079-b4eb-4325-af67-d13ac0fc6ba1

Desired behavior:

• Some argument like dcc.Tooltip direction: https://dash.plotly.com/dash-core-components/tooltip#tooltip-properties
• It should also allow diagonal/combined positions ("bottom+right")

# the python way
fig.update_traces(hoverbox_direction="right")
fig.update_traces(hoverbox_direction="left+top")

src/components/fx/hover.js の className="hovertext" を持つ g 要素とその transform の周辺から始め、次に hover 三角形の向きについて issue #7278 を確認します。"left+top" のような組み合わせ方向を含め、方向引数を hover ボックスと三角形にどのように対応付けるかを定義します; 呼び出し元が要求された trace 設定を通じてこれらの位置を選択できれば完了です。