Make dependency on maven plugin optional #1499 (#1513)

Author: EgorkaKulikov

utbot-intellij/src/main/resources/META-INF/plugin.xml

@@ -5,12 +5,12 @@
     <name>UnitTestBot</name>
     <vendor>utbot.org</vendor>
     <depends>com.intellij.modules.platform</depends>
-    <depends>org.jetbrains.idea.maven</depends>
 
     <depends optional="true" config-file="withJava.xml">com.intellij.modules.java</depends>
     <depends optional="true" config-file="withKotlin.xml">org.jetbrains.kotlin</depends>
     <depends optional="true" config-file="withPython.xml">com.intellij.modules.python</depends>
     <depends optional="true" config-file="withAndroid.xml">org.jetbrains.android</depends>
+    <depends optional="true" config-file="withIdeaMaven.xml">org.jetbrains.idea.maven</depends>
 
     <actions>
         <action id="org.utbot.intellij.plugin.ui.actions.GenerateTestsAction"

utbot-intellij/src/main/resources/META-INF/withIdeaMaven.xml

@@ -0,0 +1,3 @@
+<!--Optional dependency on org.jetbrains.idea.maven-->
+<extensions defaultExtensionNs="org.jetbrains.idea.maven">
+</extensions>