Introduce ErrorBlock component to display error text

[dvaldivia]

Replaces the repetitive instances of

<React.Fragment>
      <br />
      <Typography component="p" variant="body1" className={classes.errorBlock}>
        {errorMessage}
      </Typography>
    </React.Fragment>

with a common component

<ErrorBlock errorMessage={addError} withBreak={false} />

[Alevsk]

LGTM