fix(utils): Avoid pre_context and context_line overlap if frame lineno is out of bounds

[Lms24]

When adding context lines to a stack frame we need to handle the edge case that the frame's lineno is greater than the length of source code lines we obtained (this can happen for various reasons). We do this by assigning the last line of the source code lines array to the context_line and assigning the preceding lines as pre_context.

However, I noticed while finishing up #8699 that, that in addContextToFrame we were off by one for the pre_context line determination, causing overlap between pre_context and context_line. I'm pretty sure we want to avoid this, so this PR removes the overlap by fixing the off-by one error.

Adjusted the overlap test to show the change in behaviour and added a new one to ensure we correctly truncate too long lines.

Note, this concerns both, Node and Browser ContextLines integrations.