fix: print message on package.json parse error

[tennox]

Context: Missing comma in package.json

Current behaviour:

❯ tk dev
thread 'main' panicked at src/common/mod.rs:22:64:
called `Result::unwrap()` on an `Err` value: Error("expected `,` or `}`", line: 7, column: 5)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fish: Job 1, 'tk dev' terminated by signal SIGABRT (Abort)

New:

❯ ~/dev/ext/task-keeper/target/debug/tk dev
thread 'main' panicked at src/runners/packagejson.rs:17:45:
called `Result::unwrap()` on an `Err` value: TK-202001: failed to parse package.json
├╴at src/common/mod.rs:24:51
│
╰─▶ expected `,` or `}` at line 7 column 5
    ╰╴at src/common/mod.rs:24:51
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I'm not happy that it prints the stacktrace location twice - but I don't manage to change that... I don't know error_stack crate enough. (took me a bit to get this working 😅 )
Maybe you have a better idea, but I thought at least some way that includes the TK-202001: failed to parse package.json would be good