Split crates and clean up structure of codebase (#294)

Co-authored-by: Jiahao XU <Jiahao_XU@outlook.com>

.github/scripts/compile-settings.jq

@@ -0,0 +1,35 @@
+if $for_release then {
+  output: "release",
+  profile: "release",
+  # Use build-std to build a std library optimized for size and abort immediately on abort,
+  # so that format string for `unwrap`/`expect`/`unreachable`/`panic` can be optimized out.
+  args: ($matrix.release_build_args // "-Z build-std=std,panic_abort -Z build-std-features=panic_immediate_abort"),
+  features: ($matrix.release_features // []),
+} else {
+  output: "debug",
+  profile: "dev",
+  args: ($matrix.debug_build_args // ""),
+  features: ($matrix.debug_features // ["rustls", "fancy-with-backtrace"]),
+} end
+|
+.rustflags = (
+  if $for_release and $matrix.target == "aarch64-unknown-linux-musl" or $matrix.target == "armv7-unknown-linux-musleabihf"
+  then "-C link-arg=-lgcc -Clink-arg=-static-libgcc"
+  else "" end
+)
+|
+.features = (
+  if (.features | length > 0)
+  then "--no-default-features --features \(.features | join(","))"
+  else "" end
+)
+|
+{
+  CBIN: (if ($matrix.target | test("windows")) then "cargo-binstall.exe" else "cargo-binstall" end),
+  CTOOL: (if ($matrix."use-cross" // false) then "cross" else "cargo" end),
+  COUTPUT: .output,
+  CARGS: "--target \($matrix.target) --profile \(.profile) \(.features) \(.args)",
+  RUSTFLAGS: .rustflags,
+}
+|
+to_entries[] | "\(.key)=\(.value)"