Cleanups (#14632)

* refactor(tauri-utils): current_dest and current_pattern always change in-sync, group them to one Option

* refactor(tauri-utils): pass path as explicit argument instead of implicitly through self

* refactor(tauri-utils): remove struct field that is never set to Some

* refactor(tauri-cli): use OsString, OsStr where possible

* refactor(tauri-cli): Deref Arc early

* refactor(tauri-cli): lock config before passing to build::setup()

* refactor(tauri-build, tauri-utils): bettern pattern matching and borrowing

* refactor(tauri-cli): dont need Arc if already have static

* fix(tauri-cli): race condition initializing static flag, remove unnecessary OnceLock

* refactor(tauri-cli): use expect

* refactor(tauri-cli): remove unnecessary OnceLock

* refactor(tauri-cli): better use of dunce api

* refactor(tauri-cli): rename