Add support for storage options

[calintamas]

Hi @emeraldsanto, thank you for this great library! This PR adds support for storage options, namely:

• keychainAccessibility on iOS, via kSecAttrAccessible
• storageName, which uses kSecAttrService on iOS and fileName on Android

Both are optional and have sensible defaults (which we can change if you think it's required).

In terms of the API, I added an options object as the previous to last parameter to all methods (before the optional cb).

import EncryptedStorage, {
  KeychainAccessibility,
} from 'react-native-encrypted-storage'

await EncryptedStorage.setItem(key, value, {
    storageName: 'myStorage',
    keychainAccessibility: KeychainAccessibility.kSecAttrAccessibleWhenUnlockedThisDeviceOnly,
})

Following semver, this would be a breaking change in the function signature, so I suppose it requires a major version bump (if you agree with the API / approach).

Please let me know what you think.

[renchap]

@emeraldsanto could you have a look at this?

We are storing JWT refresh tokens in react-native-encrypted-storage and are seeing quite a lot of error -25308 on iOS (and other people in https://github.com/emeraldsanto/react-native-encrypted-storage/issues/29 do as well).

It would make a lot of sense for us to set keychainAccessibility to kSecAttrAccessibleWhenUnlocked, which this PR allows.

#91 also points a potential issue with this.

[ryeker-herndon-lark]

This would be helpful to have for our business use case as well 👍

[balsikandar]

@emeraldsanto any plans to merge this PR? This'll solve several issues all of us are facing.

[misha-pavlov]

Will this pull request be merged?

[chriswickham]

Also looking for this to be merged as it would resolve thousands of Sentry errors. Any update?

[varda-altusnova]

Any updates? @emeraldsanto

[qja0707]

I have same problem. Should I wait for merge or make patch?