fix!: Update polkadot-js/api and account for chainProperties updates

[emostov]

BREAKING CHANGE

• Document regression (breaking change) in runtime/spec response. tokenSymbol and tokenDecimals now return an Arrary<string> instead of a string. See the diff for src/services/test-helpers/responses/runtime/spec.json to view a concrete example of the change.
• Bumps dependencies, including polkadot-js
• Accounts for updates to chainProperties.chainTokens. Formerly, chainProperties.chainToken was just a string; now it is a Array<string>, so it can be extensible for chains that support multiple tokens. In this PR we make the assumption that the token at index 0 will be the native token. We consider a token native because its balance is stored in system::Accounts; opposed to a non-native token which has its balance accessible via the ORML tokens pallets.

[TarikGul]

LGTM.

[dvdplm]

I think the new format merits a test or two?

[emostov]

@dvdplm @TarikGul I added some tests and very slightly modified the service to make sure when we compare token values they are all uppercase. Previously we forced it to uppercase in the controller but I think this change is more resilient to fat finger changes in the controller.