Add SessionMiddleWare Configuration

[ElijahAhianyo]

This PR fixes a bug as described in #247. It introduces a Session middleware configuration where users can now set session config values either in the toml file or using the API. For config knobs supported upstream, this PR goes for an initial best effort of implementing only the secure config knob. Others will definitely be added later.

for toml files, it will typically look like this:

secret_key="a-secret-msg"

[middlewares]
live_load.enable = true
# add session configs here
[middlewares.session]
secure = false

using the API:

struct AdminProject;

impl Project for AdminProject {
   ...

    fn config(&self, _config_name: &str) -> cot::Result<ProjectConfig> {
        Ok(ProjectConfig::builder()
            .debug(true)
            .middlewares(
                MiddlewareConfig::builder()
                    .session(SessionMiddlewareConfig::builder().secure(false).build())
                    .build(),
            )
            .build())
    }

    ...

    fn middlewares(
        &self,
        handler: cot::project::RootHandlerBuilder,
        context: &ProjectContext<WithApps>,
    ) -> BoxedHandler {
        handler
            // call `::from_context` to use config values
            .middleware(SessionMiddleware::from_context(context))
            .build()
    }
}

[seqre]

Thank you for your contribution! Overall it looks great, I just have a single suggestion. Please make secure to be true by default, but modify cot-cli/src/project_template/config/dev.toml and set it to false there in the config template. This way we keep Cot secure by default and keep development easy.

Also, it'd be great if you could write a few additional tests to bump up the coverage.

Once you make those changes, please make the PR ready for review and we'll give our final comments!

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 4 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
cot/src/middleware.rs	66.66%	4 Missing ⚠️

Flag	Coverage Δ
rust	80.84% <85.71%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
cot/src/config.rs	87.64% <100.00%> (+1.22%)	⬆️
cot/src/middleware.rs	58.13% <66.66%> (+6.85%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[m4tx]

The change looks good, thank you a lot for confirming the issue and for the fix!

[seqre]

Great work and once again thank you for your contribution! If you want to work on SessionMiddleware supporting different stores, please take a crack at it in a separate PR ;)

[ElijahAhianyo]

Great work and once again thank you for your contribution! If you want to work on SessionMiddleware supporting different stores, please take a crack at it in a separate PR ;)

yes, definitely, would like to take up the admin issues and if no one gets to it before I do, I'd be happy to look into it :)