refactor(web): move and rename SearchResult as TokenResultMapping 🚂

[jahorton]

This is the first of four PRs designed to, in sequence, add an abstraction layer to the correction-search algorithm so that we can use the same core code to search for corrections in different ways.

In particular, up until now, we've always searched for corrections for just one token at a time - the current token. To better support whitespace fat-fingering, we'll need the ability to answer the following question: "Which tokenization pattern is the closest to matching the current text after corrections?" The core logic of the search is the same, but the backing data will be different - something that abstraction can handle well.

To accomplish the goal of abstracting the core search mechanisms, work will proceed in the following manner:

1. Relocate the code representing paths through the search graph (before making further changes).
   • refactor(web): move and rename SearchResult as TokenResultMapping 🚂 #15814 (this PR)
2. Properly return the type representing the critical metadata for processing partial + completed paths of the search graph.
   • change(web): return token-correction mapping from search-oriented methods 🚂 #15815
3. Prepare the search method for abstraction, extracting any code specific to the existing search pattern that may not work well when searching for corrections in alternative ways.
   • refactor(web): extract token-search result duplicate-filtering method 🚂 #15816
4. Abstractify the actual search method and critical metadata types.
   • feat(web): add abstraction for main correction-search algorithm, leveraged types 🚂 #15817

Build-bot: skip build:web
Test-bot: skip

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

Test Artifacts

• Web
  • KeymanWeb Test Home - build : all tests passed (no artifacts on BuildLevel "build")