feat(android_intent_plus): adds sendService method

[ViscousPot]

Description

This package already has the ability to send arbitrary intents to an activity or broadcast receiver.
This PR adds the ability to send intents to a service using sendService

Related Issues

No related issues exist for this

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I titled the PR using Conventional Commits.
• I did not modify the CHANGELOG.md nor the plugin version in pubspec.yaml files.
• All existing and new tests are passing.
• The analyzer (flutter analyze) does not report any problems on my PR.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate that with a ! in the title as explained in Conventional Commits).
• No, this is not a breaking change.

[miquelbeltran]

Thanks for the contribution! I will have to test it on my device before approving and merging. Meanwhile, there are a couple of lines that require changes.

[miquelbeltran]

Sorry this fell off my plate, I fixed the merge conflict after merging your other PR, I'll see if I can work on this soon

changes done but pending review

[miquelbeltran]

Thank you!