handle storing local data in the in-memory state

keeping `local=false` in this PR works as it aligns with the current behavior. see [here](https://github.com/adobe/aio-lib-ims/blob/master/src/ctx/Context.js#L87-L89) and [here](https://github.com/adobe/aio-lib-ims/blob/master/README.md?plain=1#L114)

**note**
In the future or as an extra effort, we may store the `local` information when [setting the token in-memory](https://github.com/adobe/aio-lib-ims/blob/master/src/ctx/StateActionContext.js#L94) to return it here. e.g. by storing it in smthg like `this.isLocal[this.keyNames.CONTEXTS][key]`. This will provide an option to just cache in-memory (not using State lib), in the context of I/O Runtime actions.

_Originally posted by @moritzraho in https://github.com/adobe/aio-lib-ims/pull/150#discussion_r1736126839_

Start with src/ctx/StateActionContext.js at line 94 to inspect how the token is stored in memory, then compare the current behavior in src/ctx/Context.js lines 87-89 and README.md around line 114. The work is complete when the local information can be retained for in-memory state and returned for the relevant context without relying on the State library.

Written by the indexing model from the issue text.