chore(eslint): ESLint setup (#6708)

chore(eslint): ESLint setup (#6708)

* chore(eslint): ESLint setup

* fix(portal): fix lint error in signer_api

* fix(library): disable no-constant-condition error in textformat

* fix(library): disable no-cond-assign error in validate_extend

* fix(library): disable no-inner-declarations error in utility

* fix(library): fix lint error in html

* fix(library): fix lint errors in clickmap

* fix(library): fix lint errors in ajax_functions_writer

* fix(library): fix lint errors in dialog

* fix(interface): fix lint errors in product_registration_service

* fix(interface): disable no-unused-labels in autosuggest

* fix(interface): fix lint errors in sendTo

* fix(interface): fix lint errors in oe-module-comlink-telehealth

* fix(interface): fix lint errors in tabs

* fix(interface): fix lint errors in fee_sheet_core

* fix(gulp): fix lint errors in gulpfile

* fix(ccdaservice): fix lint errors

* chore(eslint): pin package versions

* chore(interface): rebuild telehealth.min.js

* feat(ci): add step for ESLint