feat: add trim function for strings

Author: nafasebra

src/builtin_function/strings/trim.rs

@@ -0,0 +1,23 @@
+use crate::builtin_function::utils::{param_to_datatype, returns};
+use crate::common::data_type::DataType;
+use crate::common::errors::{ChapError, Result};
+use crate::{common::executable::ExecutableLine, runtime::Runtime};
+
+pub fn trim(runtime: &mut Runtime, executable: &ExecutableLine) -> Result<()> {
+    let p1 = param_to_datatype(runtime, executable.params.first(), executable.line_number)?;
+
+    let result = match p1 {
+        DataType::String(s) => DataType::String(s.trim().to_string()),
+        _ => {
+            return Err(ChapError::runtime_with_msg(
+                executable.line_number,
+                format!(
+                    "{} function input param should be string",
+                    executable.function_name
+                ),
+            ));
+        }
+    };
+
+    returns(runtime, executable, result)
+}