odinfmt: Option to disable the removal of empty new lines inside struct/enum body

[brainwo]

Expected:

Token_Kind :: enum {
    Heading1, // #
    Heading2, // ##
    Heading3, // ###
    Heading4, // ####
    Heading5, // #####
    Heading6, // ######
 
    Heading1Alt,
    // Heading level 1
    // ===============
    Heading2Alt,
    // Heading level 2
    // ---------------
}

After format (actual result):

New lines are removed

Token_Kind :: enum {
    Heading1, // #
    Heading2, // ##
    Heading3, // ###
    Heading4, // ####
    Heading5, // #####
    Heading6, // ######
    Heading1Alt,
    // Heading level 1
    // ===============
    Heading2Alt,
    // Heading level 2
    // ---------------
}