WD: Sequence writer in split mode should create normal names

After we have created infrastructure for collecting output files urls from every worker it will be useful to change output files urls for split mode of Write Sequence element. Curentlty, if you want to split output sequence then the names of files would be:
_ name.fa
_ name_split1.fa
_ name_split2.fa
...

It will be great if names will be:
_ name_split1.fa
_ name_split2.fa
_ name_split3.fa
...
of something like that.

Also, when you run your schema again (old split files exist) then you will see, that your new files are:
_ name_split8.fa
_ name_split9.fa
_ name_split10.fa
...

It is better to rename existing files using "oldcopy" suffix and to name new files as they are. So, in last case you will get:
_ name_split1.fa // new files
_ name_split2.fa
_ name_split3.fa
...

_ name_split1_oldcopy1.fa // renamed old files
_ name_split2_oldcopy1.fa
_ name_split3_oldcopy1.fa
...