Enable library users to detect if a smart card doesn't support PIV (#476)

* Enable library users to detect if a smart card doesn't support PIV

Closes iqlusioninc/yubikey.rs#456.

* Avoid resetting the card if we fail to select PIV or fetch version/serial

CHANGELOG.md

@@ -8,6 +8,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - `YubiKey::disconnect`
 - `impl Debug for {Context, YubiKey}`
+- `Error::AppletNotFound`
+
+### Changed
+- `Reader::open` now returns `Error::AppletNotFound` instead of `Error::Generic`
+  if the PIV applet is not present on the device. This is returned by non-PIV
+  virtual smart cards like Windows Hello for Business, as well as some smart
+  card readers when no card is present.
+- `Reader::open` now avoids resetting the card if an error occurs (equivalent to
+  calling `YubiKey::disconnect(pcsc::Disposition::LeaveCard)` if `Reader::open`
+  succeeds).
 
 ## 0.7.0 (2022-11-14)
 ### Added