Fix warnings and small issues (#1178)

try some things with no standard libraries
Add arm64 and freebsd build and tests
fix a discrepancy in the handling of chars on Arm processors

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

include/CLI/StringTools.hpp

@@ -165,7 +165,7 @@ CLI11_INLINE bool valid_name_string(const std::string &str);
 
 /// Verify an app name
 inline bool valid_alias_name_string(const std::string &str) {
-    static const std::string badChars(std::string("\n") + '\0');
+    static const std::string badChars{'\n', '\0'};
     return (str.find_first_of(badChars) == std::string::npos);
 }
 

include/CLI/TypeTools.hpp

@@ -1130,7 +1130,14 @@ bool lexical_cast(const std::string &input, T &output) {
         output = static_cast<T>(input[0]);
         return true;
     }
-    return integral_conversion(input, output);
+    std::int8_t res{0};
+    // we do it this way as some systems have char as signed and not,  this ensures consistency in the way things are
+    // handled
+    bool result = integral_conversion(input, res);
+    if(result) {
+        output = static_cast<T>(res);
+    }
+    return result;
 }
 
 /// Boolean values