Utilize same major and minor tick settings as core library

In https://github.com/chartjs/Chart.js/pull/4268 we've been talking about having the options below. Assuming this syntax is adopted, it would make sense for Chart.LinearGauge.js to utilize the same convention

```
ticks: {
minor: {}, //< use common tick options
major: {} //< use common tick options
}
```

Start by reviewing PR 4268 and the tick configuration in Chart.LinearGauge.js. Confirm the proposed syntax is adopted in the core library, then make the linear gauge use the same major and minor tick option convention; done means its tick settings follow the shared format.

Written by the indexing model from the issue text.