Use ModuleId instead of SourceId as the metrics map key

[JoshuaBatty]

Description

Fixes a critical bug where the server would crash if compilation was triggered from anything other than the root main.sw file. This was due to the metrics_map using the SourceId rather then the ModuleId as the key.

This was introduced last week in #5813 as we now need to metrics to decide if the engines should be mem swapped or discarded.

closes #5870

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 d29079c

Click to view benchmark

Test	Base	PR	%
code_action	5.5±0.06ms	5.4±0.23ms	-1.82%
code_lens	331.5±9.13ns	286.2±4.09ns	-13.67%
compile	6.1±0.03s	6.2±0.04s	+1.64%
completion	5.1±0.07ms	4.8±0.02ms	-5.88%
did_change_with_caching	6.3±0.11s	6.1±0.07s	-3.17%
document_symbol	1009.6±16.48µs	972.9±23.23µs	-3.64%
format	73.8±1.08ms	74.2±1.27ms	+0.54%
goto_definition	364.4±6.68µs	366.1±7.20µs	+0.47%
highlight	9.0±0.02ms	8.8±0.25ms	-2.22%
hover	609.1±25.62µs	603.4±18.16µs	-0.94%
idents_at_position	122.8±0.31µs	123.2±1.10µs	+0.33%
inlay_hints	663.3±11.52µs	653.0±7.54µs	-1.55%
on_enter	506.6±10.91ns	528.0±17.15ns	+4.22%
parent_decl_at_position	3.7±0.03ms	3.6±0.03ms	-2.70%
prepare_rename	375.3±6.25µs	371.2±7.12µs	-1.09%
rename	9.6±0.10ms	10.0±0.31ms	+4.17%
semantic_tokens	1035.8±19.22µs	1056.6±55.69µs	+2.01%
token_at_position	361.5±1.54µs	353.7±2.62µs	-2.16%
tokens_at_position	3.7±0.02ms	3.6±0.16ms	-2.70%
tokens_for_file	422.9±1.94µs	419.9±1.34µs	-0.71%
traverse	50.4±1.19ms	51.3±1.89ms	+1.79%

[github-actions]

Benchmark for 375c6fa

Click to view benchmark

Test	Base	PR	%
code_action	5.6±0.12ms	5.4±0.04ms	-3.57%
code_lens	328.7±9.99ns	288.3±9.12ns	-12.29%
compile	6.3±0.05s	6.3±0.03s	0.00%
completion	5.2±0.10ms	5.0±0.15ms	-3.85%
did_change_with_caching	6.3±0.08s	6.3±0.03s	0.00%
document_symbol	991.5±54.14µs	946.9±18.59µs	-4.50%
format	73.3±1.36ms	74.6±1.04ms	+1.77%
goto_definition	359.0±4.13µs	365.9±6.43µs	+1.92%
highlight	9.2±0.06ms	8.8±0.04ms	-4.35%
hover	597.5±17.93µs	612.4±27.36µs	+2.49%
idents_at_position	123.2±1.21µs	122.3±1.15µs	-0.73%
inlay_hints	660.5±20.61µs	647.9±25.85µs	-1.91%
on_enter	509.4±14.80ns	498.0±16.43ns	-2.24%
parent_decl_at_position	3.8±0.02ms	3.6±0.06ms	-5.26%
prepare_rename	358.3±6.76µs	373.5±6.62µs	+4.24%
rename	9.9±0.14ms	9.4±0.08ms	-5.05%
semantic_tokens	1027.2±14.53µs	1041.5±16.96µs	+1.39%
token_at_position	357.7±3.20µs	366.6±2.75µs	+2.49%
tokens_at_position	3.8±0.04ms	3.6±0.05ms	-5.26%
tokens_for_file	419.1±3.64µs	423.8±2.53µs	+1.12%
traverse	51.7±2.42ms	50.3±1.78ms	-2.71%