Add new --style called header-filesize and display it by default (#1988)

Also rename `header` to `header-filename`.

Related to #1701

Cargo.lock

@@ -82,6 +82,7 @@ dependencies = [
  "atty",
  "bincode",
  "bugreport",
+ "bytesize",
  "clap",
  "clircle",
  "console",
@@ -169,6 +170,12 @@ version = "1.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "439989e6b8c38d1b6570a384ef1e49c8848128f5a97f3914baef02920842712f"
 
+[[package]]
+name = "bytesize"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c58ec36aac5066d5ca17df51b3e70279f5670a72102f5752cb7e7c856adfc70"
+
 [[package]]
 name = "cc"
 version = "1.0.72"