[lldb][Editline] Support ctrl+left/right arrow word navigation.

Summary:
This adds several 5C/5D escape codes that allow moving forward/backward words similar to bash command line navigation.

On my terminal, `ctrl+v ctrl+<left arrow>` prints `^[[1;5D`. However, it seems inputrc also maps other escape variants of this to forward/backward word, so I've included those too. Similar for 5C = ctrl+right arrow.

Reviewers: JDevlieghere, labath

Reviewed By: JDevlieghere, labath

Subscribers: merge_guards_bot, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70137