STYLE: avoid unrestricted dictionary lookup in randomProcesses, waveModels

- ref issue #762

STYLE: consistency in file vs files for pointNoise and surfaceNoise

- use "files" when available, fallback to "file" otherwise.

src/waveModels/waveAbsorptionModels/base/waveAbsorptionModel/waveAbsorptionModel.C

@@ -43,7 +43,7 @@ Foam::scalar Foam::waveModels::waveAbsorptionModel::timeCoeff
     const scalar t
 ) const
 {
-    // No time ramping applied applied for absorption
+    // No time ramping applied for absorption
     return 1;
 }
 
@@ -67,12 +67,6 @@ Foam::waveModels::waveAbsorptionModel::waveAbsorptionModel
 }
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::waveModels::waveAbsorptionModel::~waveAbsorptionModel()
-{}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 bool Foam::waveModels::waveAbsorptionModel::readDict