Moves vendor commands into TockEnv (#614)

This move changes the Env trait: It removes all functionality that is
used only in vendor commands (`FirmwareProtection`, `UpgradeStorage`)
and adds a function to call when parsing CBOR commands.

The abstraction necessary to test these commands is instead realized
through compile flags. The mock upgrade storage is active when compiled
for std for example.

examples/store_latency.rs

@@ -21,7 +21,7 @@ use alloc::string::{String, ToString};
 use alloc::vec::Vec;
 use alloc::{format, vec};
 use core::fmt::Write;
-use ctap2::env::tock::{take_storage, TockStorage};
+use ctap2::env::tock::{take_storage, Storage};
 use libtock_drivers::console::Console;
 use libtock_drivers::timer::{self, Duration, Timer, Timestamp};
 use persistent_store::Store;
@@ -39,7 +39,7 @@ fn measure<T>(timer: &Timer, operation: impl FnOnce() -> T) -> (T, Duration<f64>
     (result, after - before)
 }
 
-fn boot_store(mut storage: TockStorage, erase: bool) -> Store<TockStorage> {
+fn boot_store(mut storage: Storage, erase: bool) -> Store<Storage> {
     use persistent_store::Storage;
     let num_pages = storage.num_pages();
     if erase {
@@ -55,7 +55,7 @@ struct StorageConfig {
     num_pages: usize,
 }
 
-fn storage_config(storage: &TockStorage) -> StorageConfig {
+fn storage_config(storage: &Storage) -> StorageConfig {
     use persistent_store::Storage;
     StorageConfig {
         num_pages: storage.num_pages(),
@@ -73,12 +73,12 @@ struct Stat {
 }
 
 fn compute_latency(
-    storage: TockStorage,
+    storage: Storage,
     timer: &Timer,
     num_pages: usize,
     key_increment: usize,
     word_length: usize,
-) -> (TockStorage, Stat) {
+) -> (Storage, Stat) {
     let mut stat = Stat {
         key_increment,
         entry_length: word_length,