add runtime config for redacting bytes

[skyzh]

In this PR, we export a REDACT_BYTES atomic bool globally from protobuf crate. This way, we could redact user data in log without changing too much in TiKV.

After this PR gets merged, we'll continue working on tikv/tikv#8670 to complete the redact log feature.

There's still some room for improvement for this feature, which might be worked on later.

• configure REDACT_BYTES as a crate feature
• use some kind of extra info to indicate if we should redact a field, as suggested by @yiwu-arbug

message Region {
    uint64 id = 1;
    bytes start_key = 2 [need_redact = true];
    bytes end_key = 3 [need_redact = true];
}

[skyzh]

BTW, I failed to compile these crates until I changed the dependencies specified in Cargo.toml, like this:

diff --git a/protobuf-codegen-pure-test/Cargo.toml b/protobuf-codegen-pure-test/Cargo.toml
index 5c24777..5b1ff4a 100644
--- a/protobuf-codegen-pure-test/Cargo.toml
+++ b/protobuf-codegen-pure-test/Cargo.toml
@@ -30,4 +30,3 @@ bytes = { version = "0.4", optional = true }
 
 [dependencies.protobuf]
 path = "../protobuf"
-package = "nrc-protobuf"
diff --git a/protobuf-codegen-pure/Cargo.toml b/protobuf-codegen-pure/Cargo.toml
index 4e4736c..bdf294d 100644
--- a/protobuf-codegen-pure/Cargo.toml
+++ b/protobuf-codegen-pure/Cargo.toml
@@ -16,8 +16,8 @@ doctest = false
 bench = false
 
 [dependencies]
-protobuf = { package = "nrc-protobuf", path = "../protobuf", version = "=2.8.0" }
-protobuf-codegen = { package = "nrc-protobuf-codegen", path = "../protobuf-codegen", version = "=2.8.0" }
+protobuf = { path = "../protobuf", version = "=2.8.0" }
+protobuf-codegen = { path = "../protobuf-codegen", version = "=2.8.0" }
 
 [[bin]]
 
diff --git a/protobuf-codegen/Cargo.toml b/protobuf-codegen/Cargo.toml
index 3b7aa02..9cf6903 100644
--- a/protobuf-codegen/Cargo.toml
+++ b/protobuf-codegen/Cargo.toml
@@ -19,7 +19,7 @@ A minor fork of https://github.com/stepancheg/rust-protobuf/
 bench = false
 
 [dependencies]
-protobuf = { package = "protobuf", version = "=2.8.0" }
+protobuf = { path="../protobuf" }
 heck = "0.3"
 
 [[bin]]
diff --git a/protobuf-codegen/src/bin/protobuf-bin-gen-rust-do-not-use.rs b/protobuf-codegen/src/bin/protobuf-bin-gen-rust-do-not-use.rs
index 25faa4a..fc66d27 100644
--- a/protobuf-codegen/src/bin/protobuf-bin-gen-rust-do-not-use.rs
+++ b/protobuf-codegen/src/bin/protobuf-bin-gen-rust-do-not-use.rs
@@ -1,5 +1,5 @@
 extern crate protobuf;
-extern crate nrc_protobuf_codegen as protobuf_codegen;
+extern crate protobuf_codegen;
 
 use std::fs::*;
 use std::io::Read;
diff --git a/protobuf-codegen/src/bin/protoc-gen-rust.rs b/protobuf-codegen/src/bin/protoc-gen-rust.rs
index f7509d8..97ac7d2 100644
--- a/protobuf-codegen/src/bin/protoc-gen-rust.rs
+++ b/protobuf-codegen/src/bin/protoc-gen-rust.rs
@@ -1,4 +1,4 @@
-extern crate nrc_protobuf_codegen as protobuf_codegen;
+extern crate protobuf_codegen;
 
 fn main() {
     protobuf_codegen::protoc_gen_rust_main();
diff --git a/protobuf-test-common/Cargo.toml b/protobuf-test-common/Cargo.toml
index 10141ce..1491b9d 100644
--- a/protobuf-test-common/Cargo.toml
+++ b/protobuf-test-common/Cargo.toml
@@ -34,8 +34,7 @@ lazy_static = "1.1.*"
 
 [dependencies.protobuf]
 path = "../protobuf"
-package = "nrc-protobuf"
 
 [dependencies.protobuf-codegen]
 path = "../protobuf-codegen"
-package = "nrc-protobuf-codegen"
+
diff --git a/protobuf-test/Cargo.toml b/protobuf-test/Cargo.toml
index c5c25f3..6a81711 100644
--- a/protobuf-test/Cargo.toml
+++ b/protobuf-test/Cargo.toml
@@ -30,5 +30,4 @@ serde_json   = { version = "1.0", optional = true }
 bytes = { version = "0.4", optional = true }
 
 [dependencies.protobuf]
-path = "../protobuf"
-package = "nrc-protobuf"
+path = "../protobuf"
\ No newline at end of file
diff --git a/protoc-rust/Cargo.toml b/protoc-rust/Cargo.toml
index ad61a50..e8ff6b0 100644
--- a/protoc-rust/Cargo.toml
+++ b/protoc-rust/Cargo.toml
@@ -14,9 +14,9 @@ doctest = false
 bench = false
 
 [dependencies]
-protoc = { path = "../protoc", version = "=2.8.0" }
-protobuf = { package = "nrc-protobuf", path = "../protobuf", version = "=2.8.0" }
-protobuf-codegen = { package = "nrc-protobuf-codegen", path = "../protobuf-codegen", version = "=2.8.0" }
+protoc = { path = "../protoc" }
+protobuf = { path = "../protobuf" }
+protobuf-codegen = { path = "../protobuf-codegen" }
 tempfile = "3"
 
 [package.metadata.docs.rs]
diff --git a/protoc/test-protoc/Cargo.toml b/protoc/test-protoc/Cargo.toml
index 1e36cad..f23a277 100644
--- a/protoc/test-protoc/Cargo.toml
+++ b/protoc/test-protoc/Cargo.toml
@@ -10,7 +10,7 @@ doctest = false
 bench = false
 
 [dependencies]
-protobuf = { package = "nrc-protobuf", path = "../../protobuf" }
+protobuf = { path = "../../protobuf" }
 
 [features]
 default-features = []

These changes are not included in this PR, but seems necessary to make it compile.

[yiwu-arbug]

LGTM