Reducing usage of #if CLIENT / #elif SERVER

The server will implement some classes it probably shouldn't need because certain items or game states depend on them.

BarotraumaShared/Content/blurshader.fx

@@ -0,0 +1,33 @@
+// Pixel shader applies a one dimensional gaussian blur filter.
+// This is used twice by the bloom postprocess, first to
+// blur horizontally, and then again to blur vertically.
+
+sampler TextureSampler : register(s0);
+
+#define SAMPLE_COUNT 15
+
+float2 SampleOffsets[SAMPLE_COUNT];
+float SampleWeights[SAMPLE_COUNT];
+
+
+float4 PixelShaderF(float4 position : SV_Position, float4 color : COLOR0, float2 texCoord : TEXCOORD0) : COLOR0
+{
+    float4 c = 0;
+    
+    // Combine a number of weighted image filter taps.
+    for (int i = 0; i < SAMPLE_COUNT; i++)
+    {
+        c += tex2D(TextureSampler, texCoord + SampleOffsets[i]) * SampleWeights[i];
+    }
+    
+    return c;
+}
+
+
+technique GaussianBlur
+{
+    pass Pass1
+    {
+        PixelShader = compile ps_4_0_level_9_1 PixelShaderF();
+    }
+}