Cleanup newlines and blanks in "Seaside" packages

[astares]

Similar to what is done in Pharo using pharo-project/pharo#10396
we could remove unnecessary trailing spaces and newlines also at the end of Seaside methods:

We could apply the following script:

badCases := SystemNavigation default allMethodsSelect: [ :each | each sourceCode trimRight size ~= each sourceCode size ].

fixInPackage := badCases select: [:each | each package name beginsWith: 'Seaside' ].

fixInPackage do: [:each |
	| refactoring classOrTrait |
	classOrTrait := each traitSource ifNil: [ each methodClass ] ifNotNil: [ each traitSource innerClass ].
	refactoring := RBAddMethodChange compile: each sourceCode trimRight in: classOrTrait for: nil.				 
	refactoring execute	
]