feat: remove Range Selector

This MR removes the Range Selector in favour of a list of word IDs that are part of a motif.

Example:

{
    "id": "http://ahiqar.uni-goettingen.de/ns/annotations/sample_teixml/annotation-MD16306N1l4l2l4l4l8l4",
    "type": "Annotation",
    "body": {
        "type": "TextualBody",
        "value": "Successful courtier",
        "format": "text/plain",
        "x-content-type": "Motif"
    },
    "target": {
        "source": "PLACEHOLDER → TARGET CONTENT HTML IRI",
        "selector": {
            "type": "CssSelector",
            "value": "#t_Add_2020_MD16803N1l5l3l5l5l9l6_1,#t_Add_2020_MD16803N1l5l3l5l5l11l2_1,#t_Add_2020_MD16803N1l5l3l5l5l11l2_2,#t_Add_2020_MD16803N1l5l3l5l5l11l2_3,#t_Add_2020_MD16803N1l5l3l5l5l11l2_4,#t_Add_2020_MD16803N1l5l3l5l5l11l2_5"
        }
    }
}