CSV files and other TXT files charset encoding selection needed ( `windows-1251` etc )

**Version and OS**
0.45.16 on windows 11/docker

**Is your feature request related to a problem? Please describe.**
CSV files (tables in plain text format) charset encoding selection is unsupported so content of these files may be unreadable .
Changedetection as far as I understand use UTF-8 charset for these files. The CSV files that i need to monitor are in windows-1251 charset.

**Describe the solution you'd like**
I need to have an opportunity to select correct chatset.
My CSV files are encoded in windows-1251 charset.

**Describe the use-case and give concrete real-world examples**


There are a lot of big data in CSV format. It is text format that represents the data tables by using commas or other symbols. You can see more about it on Wikipedia:
https://en.wikipedia.org/wiki/Comma-separated_values
As text files, CSV may be encoded non in UTF-8. For example, in can have windows-1251 or koi8-r charset.
CSV files that I try to use with changedetection app are unreadable due absense of charset selection
.

Start by locating the code path that reads CSV and other plain-text files, then reproduce the issue with a windows-1251 file. Identify where an encoding choice could be exposed and how decoding is currently handled. Done means users can select a charset such as windows-1251 or koi8-r and those files become readable without breaking UTF-8 files.

Written by the indexing model from the issue text.