增加自动填充支持

[blacklips]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.
这样的功能 我不知道叫啥， gboard 和 fcitx5-android支持。 希望大佬加上这个功能

[tossmilestone]

同希望能增加这个功能，不然使用bitwarden太麻烦了

[WhiredPlanck]

#1162 正在进行

[goofyz]

Reference:

https://developer.android.com/identity/autofill/ime-autofill#configure-ime
https://medium.com/bobble-engineering/integrate-autofill-with-keyboards-or-input-method-editors-c715ee4b7e1

[goofyz]

這功能我基本做好了，還欠 UI 和改善 code quality。
不過想找多些可測試的地方。除了 bitwarden login 可試多，還有什麼地方會用到這類「提議輸入」呢?