feat(core)!: replace RenderResult with buffered output model

Remove `Deref<Target=str>` and `render_text:String` in favor of
`render_buffer:Vec<(String, RenderResultMode)>` and an
`immediate_output`
flag. Add `RenderResultMode` enum, `r_eprint!`/`r_eprintln!` macros, and
new buffer manipulation methods (`append_to_buffer`, `eprint`, etc.).
Update `Display` to trim output and remove trailing newline. Migrate all
callers and tests away from `Deref` usage.

1 files changed, 4 insertions, 4 deletions

diff --git a/examples/example-unit-test/src/main.rs b/examples/example-unit-test/src/main.rs
index b85ff01..e9169df 100644
--- a/examples/example-unit-test/src/main.rs
+++ b/examples/example-unit-test/src/main.rs
@@ -42,25 +42,25 @@ mod tests {
     #[test]
     fn test_render_result_name() {
         let r = render_result_name(ResultName::new("Peter".into()));
-        assert_eq!(r.to_string().as_str(), "Hello, Peter!\n")
+        assert_eq!(r.to_string().as_str(), "Hello, Peter!")
     }
 
     #[test]
     fn test_render_error_no_name_provided() {
         let r = render_error_no_name_provided(ErrorNoNameProvided::default());
-        assert_eq!(r.to_string().as_str(), "No name provided\n")
+        assert_eq!(r.to_string().as_str(), "No name provided")
     }
 
     #[test]
     fn test_render_error_name_not_available() {
         let r = render_error_name_not_available(ErrorNameNotAvailable::default());
-        assert_eq!(r.to_string().as_str(), "Name not available\n")
+        assert_eq!(r.to_string().as_str(), "Name not available")
     }
 
     #[test]
     fn test_render_error_name_too_long() {
         let r = render_error_name_too_long(ErrorNameTooLong::new(17));
-        assert_eq!(r.to_string().as_str(), "Name too long: 17 > 10\n")
+        assert_eq!(r.to_string().as_str(), "Name too long: 17 > 10")
     }
     // --------- IMPORTANT ---------
 }