Added support for using Long-CLIP with Flux

[zer0int]

LongCLIPFluxModel, LongCLIPTextEncodeFlux -> LongCLIPTextEncodeFlux node. Also added a workflow, adapted from https://comfyanonymous.github.io/ComfyUI_examples/flux/

Feel free to rename the node - I just didn't want to 'steal' your brand. :-)

[marduk191]

sorry, i didn't realize this was a pr, the readme was because people started using you as a fork lol.

[sx0404]

We retained your node naming and feel you did a great job