Splice tool enhancements

[marinagmoreira]

• [ ] would be great to have some subtitles of the commands so that I don't have to look at the code

• [ ] there should be a save option to continue work later as sometimes we need to splice on astrobeast and we get connection broken frequently

• [ ] the percentages somehow are different, different times that you spawn the splicer with the same bag (the number of images are the same)