Fix build error when using specific or no Cargo compression features

[joseluisq]

Description

This PR fixes a build issue when SWS is used as a dependency and the Cargo compression feature is disabled completely or just some specific compression features are enabled.

Also, if only one compression feature is enabled (e.g. compression-gzip) then the preferred encoding gets re-evaluated and assigned to that compression feature format (e.g. gzip) but only if it was part of the accept-encoding request header value.

For example, now the following scenarios will work:

#....
[dependencies]
static-web-server = { version = "2.28.0", default-features = false }
# or
static-web-server = { version = "2.28.0", default-features = false, features = ["compression-brotli"] }

In addition, some logs are added/improved to reflect the changes.

Related Issue

Fixes #338

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

[semanticdiff-com]

Review changes with SemanticDiff.

Analyzed 12 of 12 files.

Overall, the semantic diff is 42% smaller than the GitHub diff.

	Filename	Status
✔️	src/compression.rs	35.24% smaller
✔️	src/compression_static.rs	3.33% smaller
✔️	src/handler.rs	46.22% smaller
✔️	src/lib.rs	51.61% smaller
✔️	src/server.rs	44.03% smaller
✔️	src/settings/cli.rs	53.8% smaller
✔️	src/settings/file.rs	53.8% smaller
✔️	src/settings/mod.rs	46.67% smaller
✔️	src/static_files.rs	40.57% smaller
✔️	src/testing.rs	Analyzed
✔️	tests/compression_static.rs	39.57% smaller
✔️	tests/static_files.rs	39.34% smaller

[palant]

Nit: you are checking for compression-deflate twice here and a bunch of other places.

[joseluisq]

Good one, yeah it has to be removed.

[palant]

Nit: With the compression feature activating the compression-brotli feature, I’m fairly certain that this change (and a bunch of similar ones) is unnecessary. Unless you are doing this for readability purposes.

[joseluisq]

Correct, I'm doing this just for readability because using compression already implies the other ones.

But it could be removed without a problem.

Feel free to clean this up if you think so.