Add streaming like write_to_file to insert_content

[KJ7LNW]

reminder discussion:

@samhvw8 said in #2510:

hmm we don't have streaming like write_to_file for this yet but we can do it

[KJ7LNW]

@samhvw8 - I found myself working on this so I will let you focus on the more important task of read_file

[samhvw8]

@KJ7LNW thanks, i make the xml style working, fixing the test, wait me a bit for that