String as integer

[jordanmontt]

Redoing #17299
Because of conflicts

This PR Does the following:

• Changed the semantics of the method String>>#asInteger Now, it returns a integer ONLY if the complete String is a valid integer, else it raises an exception.
• Deprecated String>>#asSignedInteger.
• Copied the old implementation of String>>#asInteger to String>>#extractIntegerPart. That new method behaves exactly as the old asInteger.
• Changed the semantics of String>>#asUnsignedInteger to just call String>>#asInteger and then getting the absolute value.
• Updated all senders of String>>#asInteger to call String>>#extractIntegerPart instead.
• Updated and added test to document this behevior.

This also closes #17277

[Ducasse]

Oups build fails.

[Ducasse]

We still get a problem

MetacelloNotification: Loaded -> Deprecated14 --- tonel:///builds/workspace/est_and_branch_Pipeline_PR-18503/64/src()
Error: The string '1. 379 forks on GitHub' is not a valid integer
ByteString(Object)>>error:
ByteString(String)>>asInteger
MicOrderedListBlock>>startIndexFrom:
MicOrderedListBlock>>addLineAndReturnNextNode:
MicRootBlock(MicAbstractBlock)>>newBlockFor:parent:
MicRootBlock>>addLineAndReturnNextNode:
MicrodownParser>>handleLine:
MicrodownParser>>handleLine:
MicrodownParser>>parse:
MicrodownParser class>>parse:
Microdown>>parse:
Microdown class>>parse:
MicrodownPresenter>>documentFromString:
StWelcomeTopicMicrodownPresenter>>contents:
StWelcomeBrowser>>newTopicTitle:contents:
StWelcomeBrowser>>topics
StWelcomeBrowser>>updatePresenter
StWelcomeBrowser(SpPresenter)>>initializePrivateHooks
StWelcomeBrowser(SpPresenter)>>initialize
StWelcomeBrowser class(SpPresenter class)>>newApplication:
StWelcomeBrowser class(StPresenter class)>>new
StWelcomeBrowser class>>openForRelease
BaselineOfPharo>>postload:package: