rust: Refactoring and reduce API surface

Prepare pv & pv_core crates to be released on crates.io:
* Remove any unused API to stay flexible
* Remove utils dependency
* Move cli, tmpfile and version utilities to local utils crate
* Use the new utilities in the pv tools
* Rename Secret into Confidential to avoid confusion of Secret (now
  Confidential) and AddSecret requests.
* Move the uvsecret module out of the request module and change the name
  to secret.
* Cleanup dependencies
* Precise and correct minimal dependency versions
* Inline `Aes256Key::from_digest`

The cleanup ensures that the code also compiles with the dependencies
resolved to their minimal versions using:

$ cargo +nightly -Z minimal-versions update
$ cargo build

For more information refer to this blog post:
https://users.rust-lang.org/t/psa-please-specify-precise-dependency-versions-in-cargo-toml/71277/8

Signed-off-by: Marc Hartmayer <mhartmay@de.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

rust/utils/src/lib.rs

@@ -2,7 +2,17 @@
 //! Utils for s390-tools written in rust.
 //! Not intened to be used outside of s390-tools.
 //!
-//! Copyright IBM Corp. 2023
+//! Copyright IBM Corp. 2023, 2024
+mod cli;
+mod log;
+mod tmpfile;
+
+pub use crate::cli::CertificateOptions;
+pub use crate::cli::{get_reader_from_cli_file_arg, get_writer_from_cli_file_arg};
+pub use crate::cli::{print_cli_error, print_error};
+pub use crate::cli::{STDIN, STDOUT};
+pub use crate::log::PvLogger;
+pub use crate::tmpfile::TemporaryDirectory;
 
 /// Get the s390-tools release string
 ///
@@ -28,6 +38,33 @@ macro_rules! release_string {
     }};
 }
 
+#[macro_export]
+/// Print the version to stdout
+///
+/// verbosity: integer if >0 more and more details printed
+/// feat: (optional) list of features
+/// rel_str: a string containig the release name
+macro_rules! print_version {
+    ($verbosity: expr, $year: expr $( ,$feat: expr)?) => {{
+        println!(
+            "{} version {}\nCopyright IBM Corp. {}",
+            env!("CARGO_PKG_NAME"),
+            $crate::release_string!(),
+            $year,
+        );
+        if $verbosity > 0 {
+            $($feat.iter().for_each(|f| print!("{f} ")); println!("(compiled)");)?
+        }
+        if $verbosity > 1 {
+            println!(
+                "\n{}-crate {}",
+                env!("CARGO_PKG_NAME"),
+                env!("CARGO_PKG_VERSION"),
+            );
+        }
+    }};
+}
+
 /// Asserts a constant expression evaluates to `true`.
 ///
 /// If the expression is not evaluated to `true` the compilation will fail.