Review and revise some maps' script and text labels

[Rangi42]

Follow-up to PR #367.

• Revise the Seafoam Islands script labels, like SeafoamIslandsB3FObjectMoving1Script/SCRIPT_SEAFOAMISLANDSB3F_OBJECT_MOVING1. "It all has to do with moving the boulders around. ... They were also very, very redundant here. Many routines that do practically the same thing."
• Revise the Silph Co text labels. "For all the Silph workers whose text just varies depending on whether you saved Silph, I don't think they need dialog-specific labels; just things like SilphCo7FWorkerM1BeforeText and SilphCo7FWorkerM1AfterText would do. Likewise for other NPCs who just switch between two texts based on an event."
• Name trainers' labels and constants according to their class, not their sprite. Special characters like gym leaders already do this. There's just one non-special case that already does so: in PokemonMansionB1F.asm, an OPP_BURGLAR has TEXT_POKEMONMANSIONB1F_BURGLAR, despite using SPRITE_SUPER_NERD. The rest are named after their sprite.
• Use TEXT_NAME constants in object events, not their object_const_def constants; some maps like PewterNidoranHouse.asm are incorrect here.
• Identify the remaining 71 unknown labels, like SeafoamIslands5Script_467a5.