refactor(toolkit): move the rest

[mrgrain]

Moves the the rest of shared toolkit code to the helper package and removes the toolkit-libs dependency on the CLI. Tests will be moved later to keep the diff size manageable. Code is still tested as the tests are still running from aws-cdk package.

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.26%. Comparing base (5ce3aef) to head (da16896).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #338      +/-   ##
==========================================
- Coverage   85.72%   85.26%   -0.47%     
==========================================
  Files         173      169       -4     
  Lines       22003    20524    -1479     
  Branches     2500     2284     -216     
==========================================
- Hits        18862    17499    -1363     
+ Misses       3093     2977     -116     
  Partials       48       48              

Flag	Coverage Δ
suite.unit	85.26% <100.00%> (-0.47%)	⬇️

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