Region: remove Clone from the trait, and also parameterize everything

i didn't necessarily *want* to parameterize it all,
but it turned out to be easier to do that than to force all users to
workaround the lack of Clone.

Cargo.lock

@@ -317,7 +317,6 @@ dependencies = [
  "crossterm",
  "csv",
  "dashmap",
- "dyn-clone",
  "env_logger",
  "float_eq",
  "font8x8",
@@ -554,12 +553,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "dyn-clone"
-version = "1.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "140206b78fb2bc3edbcfc9b5ccbd0b30699cfe8d348b8b31b330e47df5291a5a"
-
 [[package]]
 name = "either"
 version = "1.7.0"