AO. Make AnalysisOptionsImpl mostly immutable, and created via AnalysisOptionsBuilder.

Move analysis options construction and customization to
AnalysisOptionsBuilder, so AnalysisOptionsImpl instances can be treated
as mostly immutable after they are created.

The builder now owns mutable setup state, can be initialized from
existing options, and defensively copies mutable collections when
building final options. AnalysisOptionsImpl keeps temporary deprecated
setters for existing clients, but clears cached signatures when those
setters are used.

Update context creation to accept a builder configuration callback
instead of mutating completed options. Apply that callback before
options are stored in analysis option maps, including contexts without
an options file.

Update analysis server, analyzer CLI, plugins, bulk fixes, tools, and
tests to configure builders directly. This avoids post-construction
mutation of shared analysis options and makes option signatures more
reliable.

Change-Id: If6bffed695e0b43ae5b0355a64419b1418702034
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/512820
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>