Progress: Set up the initial structure for the remaining read tests for combining...

Progress: Set up the initial structure for the remaining read tests for combining characters.

It seems that editors make it difficult to add and manipulate combining characters.
It is possible my test files have lost combining characters without my awareness.
I might have to revisit these later on.

For now, just copy what is there to simplify the work being done.

I used commands like the following to help generate some combining characters:

```sh
echo "first valid.$(utf8 -cB U+0301)" >> basic-combining_read.txt

echo -e "  not a valid list{$(utf8 -cB U+0301)\n}" >> extended_list-combining_read.txt
```