internal/graphicsdriver/opengl: Avoid allocations by escaping to heap

internal/uidriver/glfw: Bug fix: Crashed a transparent button with th…

…e green button

Updates hajimehoshi#1822
Closes hajimehoshi#1857

internal/glfw: Add a new build tag `ebitenexternaldll` to requrie ext…

…ernal DLLs

Embedding a DLL file and extrating it on the fly can be problematic.
The application might be unexpectedly recognized as a virus by some
virus checkers.

To mitigate this issue, Ebiten adds a new build mode `ebitenexternaldll`
which prevents Ebiten from embedding DLL files. Instead, the application
will require DLL files for GLFW.

Closes hajimehoshi#1832

internal/uidriver/glfw: Wait for a FramebufferSize callback for the i…

…nitial temporary window

Updates hajimehoshi#1847

Update Oto to v2.1.0-alpha.2

Update Oto to v2.1.0-alpha.2

Update version to v2.3.0-alpha

Update version to v2.2.0-rc.1

Update dependencies

internal/uidriver/glfw: Bug fix: Forbide Maximize/MinimizeWindow on t…

…he native fullscreen on macOS

Closes hajimehoshi#1810