* Validate current node version (#19154)
* feat(12976): node version validation at runtime.
* refact(12976): move the code into a static utilities class.
* test(12976): added first test case using jest.
* test(12976): added test cases for node_version.
* feat(12976): create setup env node to bootstrap babel, ts-node and node version validator.
* refact(12976): migrated node version code from es6 to es5.
* feat(12976): node version validation at runtime.
* refact(12976): move the code into a static utilities class.
* test(12976): added first test case using jest.
* test(12976): added test cases for node_version.
* feat(12976): create setup env node to bootstrap babel, ts-node and node version validator.
* refact(12976): migrated node version code from es6 to es5.
* fix(12976): remove one level from ts node register cache directory link.
* chore(12976): added caret to semver dependecy in order to support minor versions.
* refact(12976): small change from named import to default import on node version validator.
* refact(12976): removed ts_node_register and add the code to babel_register.
* feat(12976): split eslint config in order to properly support files built to run before and after node version validator. refact(12976): convert script files to es5 code. refact(12976): delete inline eslint configs from node version check related files.
* refact(12976): remove ts node register file.
* refact(12976): completely port setup_node_env to es5.
* refact(12976): remove babel_register invokation from external dependencies in scripts.
* refact(12976): move node_version code directly into node_version_validator inside setup_node_env folder.
* refact(12976): only node version validator for kbn script.
* Fix check_file_casing babel_register reference (#19457)
* chore(12976): fixed license headers on new files.
* [precommitHook] move to dev script
* [eslint] fix lint error
* [dev/eslint] do simply boolean checks first
* [dev] use shared REPO_ROOT constant
* [dev/File] precompute relative/ext of path
* [dev/eslint] fix relative import
* [dev/eslint] fix typos
* [grunt] remove unused run:eslintStaged config
* [dev/run] only create log if we are going to use it
* [dev/run/isFailError] ensure return value is Boolean
* [dev/precommitHook] use less intermediate vars
