Implement Flood Fill Crafting Search

[jmattspartacus]

Initial commit, recommit of PR30399's code because of git issues I was unable to overcome at the time.
Adds:
map::reachable_flood_steps()

How to use
Activate the crafting menu, and see if the crafting menu includes all things within 6 tiles that are not blocked off by impassible tiles, or spaces without floors

Summary
Summary: Features "Crafting inventory now uses flood fill search"

Makes the search for items for the crafting inventory use a flood fill for the search rather than only looking for items that are within 6 tiles in a straight line.

Purpose of change
When crafting, it's nice to have things in organized containers, but with the current search, it makes it so everything either has to be on the floor, or directly in sight. With a flood fill, it's possible to organize crates or shelves in rows, and provided they are within range, the item will be added to the crafting inventory.

Describe the solution
This flood fills tiles, starting from the player's location across the entire reachable area that is passable, and then if the location is found, the items in them are added to the crafting inventory.

Describe alternatives you've considered
I've considered hooking into the pathfinding code, but I'm not sure it's the right choice for this, as I don't understand all of the code there.

Comment:
I was unable to remove the changes from PR30399 that included files completely unrelated to the PR, I tried rebasing without any luck, and ended up making the situation worse.

[OrenAudeles]

Small issues that are preventing successful compile.

[ZhilkinSerg]

Probably breaks Android build (see https://ci.narc.ro/job/Cataclysm-Android/8882/console):

0:27:35   [armeabi-v7a] Compile++ thumb: main <= inventory.cpp
10:27:35   In file included from /var/lib/jenkins/workspace/Cataclysm-Android/android/app/jni/src/inventory.cpp:1:
10:27:35   In file included from /var/lib/jenkins/workspace/Cataclysm-Android/android/app/jni/src/inventory.h:12:
10:27:35   /usr/local/android-sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include/vector:2010:21: error: object of type 'tripoint_range::point_generator' cannot be assigned because its copy assignment operator is implicitly deleted
10:27:35                   __m = __first;
10:27:35                       ^
10:27:35   /var/lib/jenkins/workspace/Cataclysm-Android/android/app/jni/src/inventory.cpp:399:23: note: in instantiation of function template specialization 'std::__ndk1::vector<tripoint, std::__ndk1::allocator<tripoint> >::insert<tripoint_range::point_generator>' requested here
10:27:35           reachable_pts.insert( reachable_pts.begin(), in_radius.begin(), in_radius.end() );
10:27:35                         ^
10:27:35   /var/lib/jenkins/workspace/Cataclysm-Android/android/app/jni/src/map_iterator.h:20:39: note: copy assignment operator of 'point_generator' is implicitly deleted because field 'range' is of reference type 'const tripoint_range &'
10:27:35                   const tripoint_range &range;
10:27:35                                         ^
10:27:35   1 error generated.
10:27:35   make: *** [/var/lib/jenkins/workspace/Cataclysm-Android/android/app/build/intermediates/ndkBuild/release/obj/local/armeabi-v7a/objs/main/inventory.o] Error 1
10:27:35   make: *** Waiting for unfinished jobs....

[jniscior]

Breaks OS X builds:

clang++  -DRELEASE -DMACOSX -DGIT_VERSION -DOSX_SDL2_LIBS -DTILES -DBACKTRACE -DUSE_HOME_DIR -ffast-math -O3 -flto -Werror -Wall -Wextra -Woverloaded-virtual -Wpedantic    -fsigned-char -stdlib=libc++  -std=c++14 -MMD -MP -mmacosx-version-min=10.13 -D_THREAD_SAFE -I/usr/local/include/SDL2 -DSDL_SOUND -I/usr/local/include/SDL2 -D_THREAD_SAFE -I/usr/local/include -c src/inventory_ui.cpp -o obj/tiles/inventory_ui.o
In file included from src/inventory.cpp:1:
In file included from src/inventory.h:12:
/Applications/Xcode_10_2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/vector:2010:21: error: object of type 'tripoint_range::point_generator'
      cannot be assigned because its copy assignment operator is implicitly deleted
                __m = __first;
                    ^
src/inventory.cpp:399:23: note: in instantiation of function template specialization 'std::__1::vector<tripoint, std::__1::allocator<tripoint>
      >::insert<tripoint_range::point_generator>' requested here
        reachable_pts.insert( reachable_pts.begin(), in_radius.begin(), in_radius.end() );
                      ^
src/map_iterator.h:20:39: note: copy assignment operator of 'point_generator' is implicitly deleted because field 'range' is of reference type 'const tripoint_range &'
                const tripoint_range &range;
                                      ^
1 error generated.