Refactor: Split use synonyms into separate maps for glob and item imports

[jjcnn]

Description

Fixes #5911 .

So far all imported items in a module have been collected in single map, with a flag in each value indicating whether it was the result of a glob/star import or an item import (this distinction matters because item imports shadow glob imports).

This PR splits the map in two: One for glob imports and one for item imports. This simplifies name resolution, and eliminates the GlobImport flag.

When another module imports all reexported items the logic is now slightly more complex, but this will be resolved once the excessive cloning of namespaces, modules and typed declarations are eliminated.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[github-actions]

Benchmark for f82e10a

Click to view benchmark

Test	Base	PR	%
code_action	6.2±0.20ms	6.3±0.22ms	+1.61%
code_lens	338.7±9.43ns	320.2±22.57ns	-5.46%
compile	6.8±0.21s	7.3±0.14s	+7.35%
completion	6.0±0.43ms	6.9±0.44ms	+15.00%
did_change_with_caching	6.8±0.13s	7.2±0.24s	+5.88%
document_symbol	1044.6±22.18µs	1011.6±40.28µs	-3.16%
format	79.3±1.15ms	79.4±1.60ms	+0.13%
goto_definition	367.2±12.64µs	371.8±10.56µs	+1.25%
highlight	9.7±0.33ms	9.7±0.34ms	0.00%
hover	610.8±13.90µs	695.3±20.57µs	+13.83%
idents_at_position	124.2±1.13µs	122.7±1.50µs	-1.21%
inlay_hints	679.6±27.60µs	671.5±38.33µs	-1.19%
on_enter	501.8±12.91ns	492.2±15.94ns	-1.91%
parent_decl_at_position	4.5±0.20ms	4.4±0.21ms	-2.22%
prepare_rename	363.7±9.69µs	369.2±8.17µs	+1.51%
rename	10.5±0.59ms	10.1±0.23ms	-3.81%
semantic_tokens	1096.0±81.56µs	1092.8±32.74µs	-0.29%
token_at_position	356.4±9.32µs	369.8±5.95µs	+3.76%
tokens_at_position	4.4±0.16ms	4.4±0.26ms	0.00%
tokens_for_file	435.7±3.38µs	426.2±3.37µs	-2.18%
traverse	52.2±2.08ms	54.4±3.16ms	+4.21%