test(angular): Increase Angular SDK test coverage.

[onurtemizkan]

Resolves: #4143

This PR increases unit test coverage of Angular SDK by integrating TestBed.

The main work here is done on tracing.ts which had low test coverage, and the previous tests were faking the angular router.

I attempted to use @testing-library/angular to be consistent with other SDK tests like @sentry/react and @sentry/svelte, but it was not possible as it doesn't support renders without compiled components which we need while testing TraceService.

Coverage before:

-----------------|---------|----------|---------|---------|-----------------------------------------
File             | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                       
-----------------|---------|----------|---------|---------|-----------------------------------------
All files        |    76.5 |    68.57 |   52.27 |   75.43 |                                         
 constants.ts    |     100 |      100 |     100 |     100 |                                         
 errorhandler.ts |   90.24 |    88.23 |     100 |   89.74 | 68,78-79,120                            
 flags.ts        |     100 |       50 |     100 |     100 | 13                                      
 index.ts        |     100 |      100 |   18.18 |     100 |                                         
 sdk.ts          |   93.33 |       60 |     100 |   93.33 | 33                                      
 tracing.ts      |   63.46 |    64.86 |   45.45 |   61.85 | ...1,87,128-133,173-188,210-233,245-264 
 zone.ts         |     100 |       50 |     100 |     100 | 12-27                                   
-----------------|---------|----------|---------|---------|-----------------------------------------

Coverage after:

------------------|---------|----------|---------|---------|-------------------
File              | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
------------------|---------|----------|---------|---------|-------------------
All files         |   97.22 |    86.02 |   88.23 |      97 |                   
 src              |   96.72 |    85.71 |   86.36 |   96.49 |                   
  constants.ts    |     100 |      100 |     100 |     100 |                   
  errorhandler.ts |   97.56 |      100 |     100 |   97.43 | 120               
  flags.ts        |     100 |       50 |     100 |     100 | 13                
  index.ts        |     100 |      100 |   45.45 |     100 |                   
  sdk.ts          |   93.33 |       60 |     100 |   93.33 | 33                
  tracing.ts      |   96.15 |    89.18 |     100 |   95.87 | 56,69-71,87       
  zone.ts         |     100 |       75 |     100 |     100 | 27                
 test/utils       |     100 |    86.95 |     100 |     100 |                   
  index.ts        |     100 |    86.95 |     100 |     100 | 50,52,80          
------------------|---------|----------|---------|---------|-------------------

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.49 KB (+0.02% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	60.29 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.11 KB (-0.01% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	53.22 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	19.83 KB (0%)
@sentry/browser - Webpack (minified)	64.56 KB (0%)
@sentry/react - Webpack (gzipped + minified)	19.85 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	44.75 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	25.94 KB (0%)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.38 KB (+0.01% 🔺)

[Lms24]

This looks great, thanks @onurtemizkan for adding Angular tests! This has been on my Angular SDK ToDo list for quite a while. Also, great that you figured out a way to get TestBed working. I tried a bunch of stuff when I was adding the router parameterization tests but didn't get it working and tabled it for "later".

I still had some questions and suggestions but overall I think we can merge this soon.

[Lms24]

Thanks for addressing my feedback! 🚀