Support concat of clip outputs for longer prompt

[KohakuBlueleaf]

wd14 tagger usually give us 77~152 tokens prompt.
But current implementation only supports 77 token length.

I try to implement an adaptive implementation which can output longer prompt when needed.
I'm not sure if this implementation is ok but it works well for me.

Some concerns:

1. Should I drop/mask all the padding tokens?
2. Should max length be an user option?