* Cleanly reimplement system/edit-config.in
- Added support for pulling config files from Docker containers.
- Added auto-detection for Docker containers.
- Use directory the script is in for target directory for config files
instead of templating it in at build time.
- Prefix error messages with `ERROR:`.
- Robustly check for a valid editor _before_ invoking it.
- Add support for actual command-line options, including a proper
`--help` option.
- Use prefix matching of absolute paths to determine file validity
instead of blindly excluding certain path types.
- If editing a non-existing file we do not provide a stock copy of,
create an empty file instead of throwing an error.
- Make the whole script properly modular.
* Improve robustness of container autodetection.
Instead of relying on the lack of certain directories on a host system,
use some relatively standard checks to determine if we appear to be
running in a container.
* Auto-detect stock config paths at runtinme instead of hard-coding them at build time.
THis will simplify testing of the script, as well as making it a bit
more resilient to users moving things around.
* Add an option to list known config files.
* Fix container environment check to not require root.
* Fix help output.
* Fix path prefix check.
* Fix file path handling.
* Use correct variable when editing files.
* Use correct path for `env`.
* Source profile before running `set -e`.
To prevent questionablly written profiles from causing the script to
exit.
* Produce columnar output when listing valid files.
* Fix copy check.
* Fix build issues.
* fix build issues
* formatting
Co-authored-by: ilyam8 <ilya@netdata.cloud>
