Bug fix and various enhancement

[j4w3ny]

Related to ARK-Builders/ARK-Navigator#10.

[kirillt]

Failure during .link creation:

[kirill@lenovo shelf]$ rm -rf /tmp/debug ; mkdir -p /tmp/debug ; RUST_BACKTRACE=1 ark-shelf-desktop2 -p /tmp/debug
[core/src/main.rs:137] &scores = []
[core/src/command/mod.rs:68] &path_list = []
6215903662141738005.link
[core/src/command/mod.rs:64] &item = DirEntry("/tmp/debug/6215903662141738005.link")
[core/src/command/mod.rs:68] &path_list = [
    "6215903662141738005.link",
]
thread 'tokio-runtime-worker' panicked at 'called `Result::unwrap()` on an `Err` value: Error { kind: Uncategorized, message: "creation time is not available for the filesystem" }', core/src/base/link.rs:157:63
stack backtrace:
   0: rust_begin_unwind
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/panicking.rs:143:14
   2: core::result::unwrap_failed
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/result.rs:1785:5
   3: <ark_shelf_desktop::base::link::Link as core::convert::From<std::path::PathBuf>>::from
   4: ark_shelf_desktop::command::read_link
   5: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   6: tokio::runtime::task::core::CoreStage<T>::poll
   7: tokio::runtime::task::harness::poll_future
   8: tokio::runtime::task::harness::Harness<T,S>::poll
   9: std::thread::local::LocalKey<T>::with
  10: tokio::runtime::thread_pool::worker::Context::run_task
  11: tokio::runtime::thread_pool::worker::Context::run
  12: tokio::macros::scoped_tls::ScopedKey<T>::set
  13: tokio::runtime::thread_pool::worker::run
  14: <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll
  15: tokio::runtime::task::harness::Harness<T,S>::poll
  16: tokio::runtime::blocking::pool::Inner::run

The invalid .link file is created in this case, which cannot be loaded neither from desktop version nor from mobile:

[kirill@lenovo tmp]$ RUST_BACKTRACE=1 ark-shelf-desktop2 -p /tmp/debug/
thread 'main' panicked at 'index out of bounds: the len is 1 but the index is 1', core/src/base/mod.rs:62:48
stack backtrace:
   0: rust_begin_unwind
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/panicking.rs:143:14
   2: core::panicking::panic_bounds_check
             at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/panicking.rs:84:5
   3: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once
   4: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter
   5: ark_shelf_desktop::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[kirillt]

This PR introduces created_time JSON field, which must be implemented in mobile version too in order to open files created in desktop version.

Update: this idea of storing created timestamp is good, but we will implement it later, after we move Rust code into arklib and wire it into ARK Shelf mobile app. Also see https://github.com/arK-Builders/arK-Navigator/issues/269 and https://github.com/arK-Builders/arK-Navigator/issues/269 for inspiration.

[kirillt]

ARK-Builders/ARK-Navigator#5 is not finished

[kirillt]

Redundant mutability