feat: Support @Terminal Context Provider and RunInTerminal Button for Jetbrains Plugin

[SoLoHiC]

Description

1. Just noticed that VS Code extension has supported that @Terminal Context Provider, but Jetbrains plugin hasn't. So I added the terminal plugin dependency and implemented the method 'getTerminalContents()' in IntelijIde.kt.
2. Since I've added that terminal plugin dependency, I digged a few on Jetbrains Docs and figured out how to implement 'paste the code to terminal', which also behaves like VS Code Extension. So, the 'runCommand()' method in IntelijIde.kt has also be implemented too now.

Checklist

• I've read the contributing guide
• The relevant docs, if any, have been updated or created
• The relevant tests, if any, have been updated or created

Screenshots

@Terminal works now, as below:

the 'RunInTerminal' button works now also:

Tests

don't really find much of tests under the extensions/intelij package. if you guys would like to provide more examples, i'd happy to follow the standards.