More visualization changes

[hendrikvanantwerpen]

A few small improvements to the visualizaton:

• Add file legend (can be toggeled by pressing f).

• Make border of clickable nodes heavier. I tried @dcreager's suggestion to lighten non-clickable nodes compared to clickable (definition, reference) nodes. I found that this would make clickable nodes very light and the graph structure became harder to see. This change will hopefully make it still easier to find clickable nodes, even when zoomed out more.

Example

[github-actions]

Performance Summary

Comparing base 8ab4184 with head 1acebc7 on typescript_benchmark benchmark. For details see workflow artifacts. Note that performance is tested on the last commits with changes in stack-graphs, not on every commit.

Before

--------------------------------------------------------------------------------
Command:            base/target/release/tree-sitter-stack-graphs-typescript index -D base.sqlite --max-file-time=30 --hide-error-details -- base/data/typescript_benchmark
Massif arguments:   --massif-out-file=perf.out
ms_print arguments: --x=72 --y=12 base-perf-results/perf.out
--------------------------------------------------------------------------------


    GB
9.150^                                             :##                        
     |                                             :#                     :   
     |                                             :#                     :   
     |                                             :#                     :   
     |                                             :# ::                  ::::
     |                                             :# :                   :: :
     |                :                          @ :# :                :  :: :
     |                :         :                @ :# :                :  :: :
     |                ::::      ::@              @::# :                ::::: :
     |                ::::      ::@              @::# :                :  :: :
     |               :::::     :::@            ::@::# :      :        ::  :: :
     |              @:::::   :::::@  :::       : @::# :     ::       :::  :: :
   0 +----------------------------------------------------------------------->Gi
     0                                                                   90.38

After

--------------------------------------------------------------------------------
Command:            head/target/release/tree-sitter-stack-graphs-typescript index -D head.sqlite --max-file-time=30 --hide-error-details -- head/data/typescript_benchmark
Massif arguments:   --massif-out-file=perf.out
ms_print arguments: --x=72 --y=12 head-perf-results/perf.out
--------------------------------------------------------------------------------


    GB
9.150^                                             ::#                        
     |                                             : #                    ::  
     |                                             : #                    :   
     |                                             : #                    :   
     |                                             : #:                   : ::
     |                                             : #:                   : ::
     |                :@                        :@ : #:                   : ::
     |                :@        :               :@ : #:                   : ::
     |                :@::      :::             :@:: #:                 ::: ::
     |                :@::    : :::             :@:: #:                 : : ::
     |               ::@::    :::::            ::@:: #:      :        ::: : ::
     |              @::@::    :::::   :       :::@:: #: :   ::       @::: : ::
   0 +----------------------------------------------------------------------->Gi
     0                                                                   90.11