Ktor headers case-insensitive, set append

gistfile1.txt

    headers {
        set("header-abc", "abc")
        set("header-ABC", "ABC")
        append("header-xyz", "xyz")
        append("header-XYZ", "XYZ")
    }
    
    2024-01-10 11:53:39.983 [outine#6] INFO  io.ktor.client.HttpClient
    - REQUEST: https://ktor.io/docs/welcome.html
    METHOD: HttpMethod(value=GET)
    COMMON HEADERS
    -> Accept: application/json
    -> Accept-Charset: UTF-8
    -> header-abc: ABC
    -> header-xyz: xyz; XYZ
    CONTENT HEADERS
    -> Content-Length: 0
    BODY Content-Type: null
    BODY START
    
    BODY END