implement delete files in deepset Cloud workflow

[ArzelaAscoIi]

AC: delete method that allows deleting by:

• query (filters), all files, names
• TBD

[elundaeva]

@ArzelaAscoIi our Cambridge contact has also asked about deleting files via SDK - would be great if this got implemented :) For now I'll redirect him to the relevant API endpoint

[ArzelaAscoIi]

@gosiapre

[gosiapre]

I don't think I have the rights to add production label in this repo so it's visible in our backlog