feat: Relates to #360. Only allow import from Parity Signer chain account matching current chain. ETC support (#483)

* feat: Relates to #360. Only allow import from Parity Signer chain account matching current chain. ETC support

* review-fix: Refer to non-Parity chain names in the UI. Add console.error

* review-fix: Do not need to chcek health status before calling chainId RPC of light.js on pages accessed through navigation

* review-fix: Rename function name that matches current chain id with imported chain id of address

* review-fix: Remove unnecessary function

* review-fix: Rename function to accountAlreadyExists

* review-fix: Remove FIXME. See https://github.com/paritytech/fether/pull/483#discussion_r270834847

* review-fix: Refactor to use util functions isEtcChainId, chainIdToString, isNotErc20TokenAddress

* fix: Fix typo in comment

* review-fix: Change wording of parity phrase comment

* review-fix: Do not clear isImport as not account related

* fix: Clear error so error when recover from seed phrase not still shown if then click to recover from QR code

* fix: Rename so signerChainId correctly destructured and not undefined

* review-fix: Remove async/await from clear

* fix: Avoid mapping signer chain id to chain name since too much maintenance with Parity Ethereum

* review-fix: Remove await from createAccountStore

* tests: Add colour to fether-react tests

* refactor: No need to parseInt on the signerChainId

* refactor: Use isNotErc20TokenAddress

* refactor: Use isNotErc20TokenAddress again

* refactor: Add isErc20TokenAddress util so more readable

* fix: Replace valueOf with .eq. Fix so obtain BN from props

* refactor: Combine into single if statement when checking if valid Eth/Etc address

* refactor: Update utils without unnecessary return block

* chore: Update to latest React 16.8.3 to requirements of react-i18next

* feat: Scaffold basic translation with English and German

* feat: Relates to #402. German translation fully working

* fix: Switch back to English by default

* fix: Allow user to switch between languages in preferences of context menu

* feat: Translate the context menus

* refactor: Remove German language. Add as separate PR

* refactor: Remove blank line

* feat: Add German language using Google Translate only

* fix: Fix Fether menu German language translation after review from @Robbepop (native German speaker)

* docs: Update Readme with Internationalisation Add New language instructions

* docs: Update Readme with Known Issues and Usage instructions

* review-fix: Disabled tooltip Please fill out this field. Add High and Low tx speed

* review-fix: Update license headers to be 2019 instead of 2018

* review-fix: Change ns1 to fether-electron and fether-react. Use pino.debug

* fix: Add missing i18n conversion for macOS Edit menu

* review-fix: Remove unused i18next browser languagedetector dependency

* merge latest from master and fix conflicts

* merge latest master and fix conflicts. TODO do not expose remote

* fix: Do not expose remote. Only expose add and remove listener, and reload via bridge

* feat: Convert new release available text to i18n