use a single function for saving images with metadata both in extra networks and main mode for #10395

add slider for token merging for img2img
rework StableDiffusionProcessing to have the token_merging_ratio field
fix a bug with applying png optimizations for live previews when they shouldn't be applied

Should fix #10416

only download TAESD model when it's needed
return calculations in single_sample_to_image to just if/elif/elif blocks
keep taesd model in its own directory

update extensions table: show branch, show date in separate column, and show version from tags if available

load extensions' git metadata in parallel to loading the main program to save a ton of time during startup

add a bit of spacing/styling to settings elements
add link info for token merging

Required by self-attn guidance extension
https://github.com/ashen-sensored/sd_webui_SAG

Localization fixes

Allow web UI to be ran fully offline

Allow bf16 in safe unpickler