* Update eslint related packages
* add errorMessage to no-restricted-paths validation
* add license to eslintrc file
* ignore broken plugin fixture
* upgrade tangled peer deps
* give name to unnamed func to avoid typescript-eslint/typescript-eslint#1078
* migrate away from removed prefer-interface
* migrate away from removed no-angle-bracket-type-assertions rule
* migrate away from removed no-triple-slash-reference rule
* old config was invalid and made this rule a noop
* fix array-type rule config
* fix readonly paramProperties that weren't being checked
* fix propType ordering
* remove references to non-existent rules
* remove unnecessary disable that is improperly formatted
* fix comment-related spacing
* fix typo/invalid namespace overrides
* rename fn to avoid hook-alike behavior
* remove reference to old removed rule
* use caret version for prettier
* reference babel-eslint with absolute path
* Warn in Typescript when using Array.flat() or .flatMap() without polyfill
* Update ecma version provided to babel in eslint
* Update per review comments
* restrict import from core&plugin internals
* Fork import/no-restricted-paths and add allowSameFolder option
Our use case requires to restrict imports from plugin folders, which names are unknown for us yet. We cannot use 'import/no-restricted-paths' in the current state, because if we define 'from: plugins/*/server/' the rule will report all relative imports in the same folder as well. To fix this problem we added another option 'allowSameFolder' that makes the rule to ignore imports in the same folder.
* update notices
* add basePath option
* support glob pattern instead of reagexp
* remove @notice, make basePath required
* [@kbn/expect] "fork" expect.js into repo
* [eslint] autofix references to expect.js
* [tslint] autofix all expect.js imports
* now that expect.js is in strict mode, avoid reassigning fn.length
I'd like to add another custom eslint rule, but there isn't a very good place to do that right now. We have the `eslint-plugin-kibana-custom` package, which is super simple but isn't in the `@kbn` namespace and isn't included in the root eslint config, and `@kbn/eslint-plugin-license-header` is too specific, so I've merged those two packages into `@kbn/eslint-plugin-eslint`, which is a little redundant but allows is to refer to the rules within it as `@kbn/eslint/{rule}`, which feels nice.
Thoughts?
_**NOTE:**_ merging the eslint rules from the two packages means enabling prettier for the code from `@kbn/eslint-plugin-license-header`, all those changes are made in 42c7da6fe2. [View the changes without the prettier updates](b647f2b...74e07a0)
