Bug: StreamToFile's readUntil always returns lines from the start of the file

[TB-1993]

Problem/Opportunity

The StreamToFile's readUntil method returns all lines up to (and including) the line containing the search string.

Steps to reproduce

No response

Expected Behavior

It's expected that the readUntil method would only search and return the lines that haven't previously been searched/returned.

For example if we had the follow log

1 This
2 Is
3 An
4 Example
5 Of
6 A
7 Log
8 File

And the readUntil method was first called to search for the string "Example" it should return lines 1-4.
If the readUntil method was called again after that searching for the string "Log" it should return lines 5-7.

Actual Behavior

All lines from the start of the file up to and including the line matching the search string are being returned when a match is found.

Notes (Optional)

No response