Fixed MSAL-Node HttpClient AAD-Server-Error-500 Bug

[Robbie-Microsoft]

Previous refactor of MSAL-Node's HttpClient was not tested with an actual 500 error from an AAD server. After using Fiddler Everywhere to further test HttpClient and simulate a 500 error from an AAD server, it was discovered that a 500 error returned from an AAD server would break the application. This PR covers additional functionality in HttpClient to address a 500 error returned from an AAD server.

[codecov-commenter]

Codecov Report

Merging #5342 (c17d95a) into dev (1aac88b) will increase coverage by 0.02%.
The diff coverage is 92.50%.

Flag	Coverage Δ		*Carryforward flag
msal-angular	96.50% <ø> (ø)		Carriedforward from 1aac88b
msal-browser	86.47% <ø> (ø)		Carriedforward from 1aac88b
msal-common	85.45% <ø> (ø)		Carriedforward from 1aac88b
msal-core	82.84% <ø> (ø)		Carriedforward from 1aac88b
msal-node	83.37% <92.50%> (+0.46%)	⬆️
msal-node-extensions	76.03% <ø> (ø)		Carriedforward from 1aac88b
msal-react	94.50% <ø> (ø)		Carriedforward from 1aac88b
node-token-validation	88.88% <ø> (ø)		Carriedforward from 1aac88b

*This pull request uses carry forward flags. Click here to find out more.

Impacted Files	Coverage Δ
lib/msal-node/src/network/HttpClient.ts	92.85% <89.28%> (+0.33%)	⬆️
lib/msal-node/src/utils/Constants.ts	100.00% <100.00%> (ø)
lib/msal-node/src/utils/NetworkUtils.ts	100.00% <100.00%> (ø)

[sameerag]

Added a few comments, mostly around code structure and readability.

[Robbie-Microsoft]

This was not being used anywhere.

[sameerag]

Added one final comment to complete the status checks and error assignments. Approving though.

[ghost]

🎉@azure/msal-node@v1.14.4 has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes
• Official NPM Release