Fix Lint warnings

[Tbaut]

At the time of writing:

• parity-signer/src/components/PayloadDetailsCard.js 159:39 warning 'methodArgs' is already declared in the upper scope no-shadow

• parity-signer/src/screens/AccountNew.js 151:22 warning 'name' is already declared in the upper scope no-shadow 158:10 warning 'derivationPassword' is already declared in the upper scope no-shadow 159:10 warning 'derivationPath' is already declared in the upper scope no-shadow 160:10 warning 'isDerivationPathValid' is already declared in the upper scope no-shadow

• parity-signer/src/screens/AccountRecover.js 214:21 warning 'name' is already declared in the upper scope no-shadow 232:21 warning 'seedPhrase' is already declared in the upper scope no-shadow 245:9 warning 'derivationPassword' is already declared in the upper scope no-shadow 246:9 warning 'derivationPath' is already declared in the upper scope no-shadow 247:9 warning 'isDerivationPathValid' is already declared in the upper scope no-shadow

• parity-signer/src/stores/ScannerStore.js 260:11 warning 'missedFrames' is already declared in the upper scope no-shadow

• parity-signer/src/util/decoders.js 297:25 warning Unexpected use of '>>' no-bitwise 297:37 warning Unexpected use of '&' no-bitwise

• parity-signer/src/util/decoders.spec.js 100:1 warning Skipped test suite jest/no-disabled-tests

• parity-signer/src/util/strings.js 23:9 warning Unexpected control character(s) in regular expression: \x00 no-control-regex

[hanwencheng]

addressed in #431