concatenation

Apply low-risk performance optimizations across multiple bundles:

Loop optimizations - cache method results:
- StyledString: Cache otherRuns.size() before loop
- ContributionManager: Cache contributions.size() in indexOf() and
duplicate removal
- ContentProposalAdapter: Cache autoActivateString.length() in loop
- DialogSettings: Cache s.length() before character iteration
- MenuManagerShowProcessor: Cache menuModel.getChildren() to avoid
repeated calls
- WorkbenchPage: Cache getChildren() results to avoid expensive repeated
calls

String concatenation optimizations:
- WizardsRegistryReader: Use StringBuilder for path construction in loop
- NewContentTypeDialog: Use StringBuilder for name generation in while
loop

Repeated expensive calls:
- BindingManager: Cache format().length() results in comparison
- MenuManagerShowProcessor: Cache getChildren() in loop condition and
body

All changes are non-API breaking and maintain identical behavior while
reducing unnecessary object allocations and method calls.