Implement Integral Data Types (#13)

**Rationale:**

Integral Types were missing and are needed for Project Nautilus.

**Changes:**

- Implements Integral Data Types
  - u64 and i64 implemented through bigint

Reviewed-on: #13
Co-authored-by: Sergey Savelyev <sergeysav.nn@gmail.com>
Co-committed-by: Sergey Savelyev <sergeysav.nn@gmail.com>

server/src/http/error.rs

@@ -23,6 +23,8 @@ pub enum HttpServerResultError {
     PanelUuidNotFound { uuid: Uuid },
     #[error(transparent)]
     Command(#[from] crate::command::error::Error),
+    #[error("Command Not Found: {cmd}")]
+    CmdNotFound { cmd: String },
 }
 
 impl ResponseError for HttpServerResultError {
@@ -36,6 +38,7 @@ impl ResponseError for HttpServerResultError {
             HttpServerResultError::InternalError { .. } => StatusCode::INTERNAL_SERVER_ERROR,
             HttpServerResultError::PanelUuidNotFound { .. } => StatusCode::NOT_FOUND,
             HttpServerResultError::Command(inner) => inner.status_code(),
+            HttpServerResultError::CmdNotFound { .. } => StatusCode::NOT_FOUND,
         }
     }
     fn error_response(&self) -> HttpResponse {