Cache overviews by characterName and realm instead of raiderId

[LinusPhoenix]

If the same wow character is in raid teams A and B and there is a cached overview for that character in raid team A, requesting the overview of that character in raid team B will not use the cached version since the raiderId is different for the character in each raid team.

We do not store any raid-team specific information in the overview, so we can safely cache overviews on a per-character basis instead of a per-raider basis.

This would reduce the amount of requests that need to go to the Blizzard API.

[karifrederiksen]

The getOverview method currently takes a raidTeamId and a raiderId as parameters, which are used to look up the character's name, realm, and region.

getOverview(
        @ReqUser() user: User,
        @Param("raidTeamId") raidTeamId: string,
        @Param("raiderId") raiderId: string,
        @Query("caching") useCaching: string,
    ): Promise<RaiderOverviewDto>

If RaiderOverviewDto only contains information available from Blizzard's API, then maybe we should change the parameters to characterName, realm, and region to simplify the lookup and caching logic.

[LinusPhoenix]

The only field preventing us from caching on character basis instead of raider basis is the raider's role in the team, which is already covered by the /raiders and /raiders/<raiderId> endpoints. We can remove that field and change the caching logic as desired.

Regarding the raid team and raider lookup, we could do this as well, however there is no tangible benefit yet to make the character overviews accessible outside of the raid team context, so I wouldn't do it yet.