Add `Rascal Does Not Dream of` movie set and map movies as specials

[plantysnake]

AniDB	TVDB/TMDB/IMDB	Notes
https://anidb.net/anime/17640	https://thetvdb.com/index.php?tab=series&id=345596	Map movie as tvdb special
https://anidb.net/anime/17862	https://thetvdb.com/index.php?tab=series&id=345596 https://www.themoviedb.org/movie/1086591 https://www.imdb.com/title/tt28036417	Map movie as tvdb special and map to IMDB and TMDB

Added movie set, but the naming is kinda iffy.

[i-strelnikov]

Using the episodeoffset keeps things simpler.

@BrutuZ Should I also change

<anime anidbid="14397" tvdbid="345596" defaulttvdbseason="0" episodeoffset="" tmdbid="" imdbid="tt10472884">
  <name>Seishun Buta Yarou wa Yumemiru Shoujo no Yume o Minai</name>
  <mapping-list>
    <mapping anidbseason="1" tvdbseason="0">;1-6;</mapping>
  </mapping-list>
</anime>

to

<anime anidbid="14397" tvdbid="345596" defaulttvdbseason="0" episodeoffset="6" tmdbid="" imdbid="tt10472884">
  <name>Seishun Buta Yarou wa Yumemiru Shoujo no Yume o Minai</name>
</anime>

?

[BrutuZ]

Yesn't, switching from mapping-list is fine, but the number is wrong. It's an offset (final value = offset + original episode number)

Unrelated: Didn't realize there were that many Movies\OVAs released o_O

[BrutuZ]

LGTM