fix(OpenGL/Framebuffer): release owned resources on delete

[PaulHax]

Context

vtkFramebuffer.populateFramebuffer() creates a color texture and a depth renderbuffer that nothing ever frees: releaseGraphicsResources() deletes the framebuffer but not the attachments, and delete() never calls it. Every torn-down consumer (hardware selector, volume mapper, render passes) leaks a full-window RGBA texture and DEPTH_COMPONENT16 renderbuffer.

Results

Releasing or deleting a framebuffer now frees everything populateFramebuffer created along with the GL framebuffer; the live WebGL object count returns to baseline in the new tests. Caller-supplied attachments stay borrowed. Nulling glFramebuffer on release also repairs the getSize()/getGLFramebuffer() resize checks in OpenGL/VolumeMapper, ForwardPass, Convolution2DPass and RadialDistortionPass, which previously reused a deleted framebuffer object.

Changes

• The framebuffer tracks ownership of the texture and depth renderbuffer populateFramebuffer() creates and frees them on releaseGraphicsResources(), which is now chained into delete(). When the render window is already deleted but the shared GL context is still alive (multi-view teardown order), the owned texture is freed directly on the context.
• removeColorBuffer clears the slot instead of splicing. The previous code shifted later entries down, desynchronizing array indices from GL color attachment points (COLOR_ATTACHMENT0 + n) for consumers using multiple attachments (SurfaceLIC attaches 0, 2, 3). bind() skips empty slots.
• create() re-binds the new framebuffer when the one it released was bound: deleting a bound framebuffer resets the GL binding to the default, which would send bind-then-create callers (SurfaceLIC) rendering to the canvas.
• populateFramebuffer still releases attachments before creating new ones. That is redundant with create() at every current call site, but it is what keeps a repeat populateFramebuffer() from leaking, and both paths now share one releaseAttachments() implementation.
• Documentation and TypeScript definitions were updated to match those changes

PR and Code Checklist

• semantic-release commit messages
• Run npm run reformat to have correctly formatted code