Merge pull request #4849 from bruntib/new_features

[gui] New features page for 6.28.0

Merge pull request #4838 from dkrupp/password_env

Enable passing credentials from env var

[fix] Fix invisible chars in error plist (#4809)

When either the standard input/output or compilation command contains an
invisible character then plist dump fails.

[version] Bump up version 6.27.3

Added flags to set server processes

Added --api-handler-processes and --task-worker-processes server flags.
Using these flags overrides the corresponding values in the server
config file.

[fix] semver.Version doesn't have strip()

The `get_binary_version()` now returns `semver.Version` instead of `str`.
However, at two places the changes were not properly adatped, where we
still assumed a string.

Merge pull request #4725 from gulyasgergely902/new-features-6-27

[feature] Add new 6.27.0 version highlights to CodeChecker

Increase TCP backlog size

[version] Bump up version to 6.27.0-rc1

[version] Upgrade psutil to 5.9.8