(ngx-features-viewer) Project template for right label

[damiclem]

Allow users to define their custom template on the right side of the plot, the same way it can be done on the left side. Example:

<ngx-features-viewer>
    <!-- Define template for label on the left side -->
    <!-- NOTE by default falls back to left side -->
    <ng-template [ngx-features-viewer-label]="left"></ng-template>
    <ng-template [ngx-features-viewer-label]></ng-template>
    <!-- Define template for label on the right side -->
    <ng-template [ngx-features-viewer-label]="right"></ng-template>
</ngx-features-viewer>

This should change the label property in NgxFeaturesViewerLabelDirective from this:

    @ContentChild(NgxFeaturesViewerLabelDirective)
    public label?: NgxFeaturesViewerLabelDirective;

to this:

    @ContentChild('ngx-features-viewer-label, ngx-features-viewer-label[left]')
    public 'label.left'?: NgxFeaturesViewerLabelDirective;

    @ContentChild('ngx-features-viewer-label[right]')
    public 'label.right'?: NgxFeaturesViewerLabelDirective;

Therefore, it must be handled in the DrawService.draw$ and DrawService.drawn$ pipelines accordingly.