[Feat]: Support padding in FitViewOptions

[Rey-Wang]

Describe the feature / 功能描述

现在调用 FitView 方法，会从 x 和 y 的 0 开始自动缩放，是否可以提供 padding 的配置项，能够留有一定的空间来做 fitView

Are you willing to contribute? / 是否愿意参与贡献？

Please select / 请选择

[yvonneyx]

可以通过在 spec 中指定 padding 来满足你的诉求

https://g6.antv.antgroup.com/api/graph/option#padding

[github-actions]

Since the issue is missing key information and has been inactive for 7 days, it has been automatically closed. If you wish to see the issue reopened, please provide the missing information. | 由于该 issue 缺少关键信息且已闲置 7 天，现已自动关闭。如需重新打开此问题，请提供所缺失的信息。。