[EuiBasicTable] add nameTooltip API

[alexwizp]

This feature request is based on this comment and suggests adding a new nameTooltip API for EuiBasicTable.

Example:

const columns = [
  {
    field: 'github',
    name: 'Github',
    nameTooltip: {
      content: 'Their mascot is Octokitty',
      icon: 'questionInCircle', // default icon, but can be customized
      iconProps: { color: 'subdued' }, // allows customizing the icon color/size etc if needed
      tooltipProps: { position: 'bottom' }, // allows additional tooltip configuration
    },
    render: (username: User['github']) => (
      <EuiLink href="#" target="_blank">
        {username}
      </EuiLink>
    ),
  },
];