Fix visibility of whitespace in config output

[schneems]

When a config var has whitespace (especially trailing whitespace) it is hard to see. This commit wraps the values (if they exist) in a character so the difference is visually observable:

Before:

$ export PHP_INI_SCAN_DIR="/opt/homebrew/etc/php/8.4/conf.d         "
$ ./sapi/cli/php --ini
Configuration File (php.ini) Path: /usr/local/lib
Loaded Configuration File:         /opt/homebrew/etc/php/8.4/conf.d         
Scan for additional .ini files in: (none)
Additional .ini files parsed:      (none)

Note

The above output has trailing whitespace that is not visible, you can see it if you copy it into an editor.

After:

$ ./sapi/cli/php --ini
Configuration File (php.ini) Path: "/usr/local/lib"
Loaded Configuration File:         "/opt/homebrew/etc/php/8.4/conf.d         "
Scan for additional .ini files in: (none)
Additional .ini files parsed:      (none)

Above the whitespace is now visible /opt/homebrew/etc/php/8.4/conf.d .

Close #18390

[TimWolla]

Thank you for the PR. I think I would prefer double quotes as the indicator, as this would make the entire value copy and pasteable into a terminal without causing issues, i.e. I can just use the value and run vim "whatever I copied" to view a config file.

[schneems]

@TimWolla seems good. I initially picked a backtick due to code literal format for markdown like this but I also agree that it's helpful to have a quote right there, especially for cases like "/dirs/like this that have spaces/in them" where copying and pasting the dir into a shell (a likely use case) would fail and the different segments might be treated as multiple arguments.

I'll generally defer character choice as a style decision for primary project maintainers/contributors. Updated with a new commit and description to match.