supersize: Add Print(idx). Sort subgroups in canned_queries.

tools/binary_size/libsupersize/testdata/Console.golden

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 Entering interactive Python shell. Quick reference:
 
 SizeInfo: metadata, raw_symbols, section_sizes, symbols
 Symbol: FlagsString, IsBss, IsGeneratedByToolchain, IsGroup, address, aliases, end_address, flags, full_name, generated_source, is_anonymous, name, num_aliases, object_path, padding, pss, pss_without_padding, section, section_name, size, size_without_padding, source_path, template_name
 
-SymbolGroup (extends Symbol): CountUniqueSymbols, Filter, GroupedBy, GroupedByName, GroupedByPath, GroupedBySectionName, Inverted, IterLeafSymbols, IterUniqueSymbols, Sorted, SortedByAddress, SortedByCount, SortedByName, WhereAddressInRange, WhereFullNameMatches, WhereGeneratedByToolchain, WhereHasAnyAttribution, WhereHasPath, WhereInSection, WhereIsGroup, WhereIsTemplate, WhereMatches, WhereNameMatches, WhereObjectPathMatches, WherePathMatches, WherePssBiggerThan, WhereSizeBiggerThan, WhereSourceIsGenerated, WhereSourcePathMatches, WhereTemplateNameMatches, is_sorted
+SymbolGroup (extends Symbol): CountUniqueSymbols, Filter, GroupedBy, GroupedByName, GroupedByPath, GroupedBySectionName, Inverted, IterLeafSymbols, IterUniqueSymbols, SetName, Sorted, SortedByAddress, SortedByCount, SortedByName, WhereAddressInRange, WhereFullNameMatches, WhereGeneratedByToolchain, WhereHasAnyAttribution, WhereHasPath, WhereInSection, WhereIsGroup, WhereIsTemplate, WhereMatches, WhereNameMatches, WhereObjectPathMatches, WherePathMatches, WherePssBiggerThan, WhereSizeBiggerThan, WhereSourceIsGenerated, WhereSourcePathMatches, WhereTemplateNameMatches, is_sorted
 
 SymbolDiff (extends SymbolGroup): DiffStatus, IsAdded, IsChanged, IsRemoved, IsUnchanged, WhereNotUnchanged, added_count, changed_count, removed_count, unchanged_count
 
 canned_queries: CategorizeByChromeComponent, CategorizeGenerated, TemplatesByName
 
 Functions: Diff(), Disassemble(), ExpandRegex(), Print(), ShowExamples()
 Variables: canned_queries, printed, size_info
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 # Show pydoc for main types:
 import models
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 39)  43785380 (100.0%) b@0x0        131072  third_party/fft_fixed.cc
              ff_cos_131072_fixed
 40)  43785380 (100.0%) b@0x0        131072  third_party/fft_float.cc
              ff_cos_65536
 41)  43785380 (100.0%) b@0x2dffda0  28      third_party/icu/ucnv_ext.c
              g_chrome_content_browser_client
 42)  43785380 (100.0%) b@0x2dffe80  200     third_party/icu/ucnv_ext.c
              SaveHistogram::atomic_histogram_pointer
 43)  43785380 (100.0%) b@0x2dffe84  4       third_party/icu/ucnv_ext.c
              g_AnimationFrameTimeHistogram_clazz