Engine-Q Updates

- jt created ["maybe text codec" version 2](https://github.com/nushell/engine-q/pull/871), and [Harden highlighter against alias spans](https://github.com/nushell/engine-q/pull/867), and [Move history search to ctrl-x](https://github.com/nushell/engine-q/pull/864), and [Allow equals to separate long flag and arg](https://github.com/nushell/engine-q/pull/858), and [Also set $in-variable with input](https://github.com/nushell/engine-q/pull/856), and [Allow let/let-env to see custom command input](https://github.com/nushell/engine-q/pull/854), and [Add -c flag and others to cmdline args](https://github.com/nushell/engine-q/pull/853), and [Start support for commandline args to nu itself](https://github.com/nushell/engine-q/pull/851), and [Port exec command](https://github.com/nushell/engine-q/pull/849), and [Port default command](https://github.com/nushell/engine-q/pull/848), and [Fix expanding external args](https://github.com/nushell/engine-q/pull/847), and [Fix bug in date comparison](https://github.com/nushell/engine-q/pull/842), and [Allow `open` to read its filename from input](https://github.com/nushell/engine-q/pull/841), and [Allow external args to expand globs](https://github.com/nushell/engine-q/pull/839), and [Highlight help tutor](https://github.com/nushell/engine-q/pull/838), and [Add var vals and alias expansions to scope var](https://github.com/nushell/engine-q/pull/837), and [Only escape backslash on windows](https://github.com/nushell/engine-q/pull/825), and [Add flag completions](https://github.com/nushell/engine-q/pull/817), and [Fix doc comments for custom commands](https://github.com/nushell/engine-q/pull/815), and [Make external app error uniform](https://github.com/nushell/engine-q/pull/812) - sholderbach [added F1-F12 key support](https://github.com/nushell/engine-q/pull/866), and [Accomodate reedline#270](https://github.com/nushell/engine-q/pull/863) - eggcaker [fixed into datetime example parameter type](https://github.com/nushell/engine-q/pull/862), and [allow fetch command to add custom headers](https://github.com/nushell/engine-q/pull/840), and [Add how to setup oh-my-posh with engine-q document](https://github.com/nushell/engine-q/pull/810) - elferherrera created [using menu trait](https://github.com/nushell/engine-q/pull/861), and [History menu](https://github.com/nushell/engine-q/pull/846)

Updates to the engine-q project include contributions from jt, sholderbach, eggcaker, and elferherrera. These changes encompass a variety of improvements, such as text codec enhancements, highlighter hardening, history search improvements, argument parsing enhancements, command porting, bug fixes, glob expansion, help tutor highlighting, scope variable additions, backslash escaping, flag completions, documentation fixes, external app error uniformity, F1-F12 key support, reedline accommodation, datetime parameter type fixes, custom header support for fetch commands, oh-my-posh setup documentation, and the implementation of a history menu.