Add analyze imports libs (SPICE-0001) (#695)

This adds a new feature to build a dependency graph of Pkl programs, following the SPICE outlined in https://github.com/apple/pkl-evolution/pull/2.

It adds:
* CLI command `pkl analyze imports`
* Java API `org.pkl.core.Analyzer`
* Pkl stdlib module `pkl:analyze`
* pkl-gradle extension `analyze`

In addition, it also changes the Gradle plugin such that `transitiveModules` is by default computed from the import graph.

pkl-core/src/main/resources/org/pkl/core/errorMessages.properties

@@ -635,6 +635,9 @@ Expected an exception, but none was thrown.
 cannotEvaluateRelativeModuleUri=\
 Cannot evaluate relative module URI `{0}`.
 
+cannotAnalyzeRelativeModuleUri=\
+Cannot analyze relative module URI `{0}`.
+
 invalidModuleUri=\
 Module URI `{0}` has invalid syntax.
 
@@ -1060,3 +1063,6 @@ To fix this problem, add dependendy `org.pkl:pkl-certs`.
 # suppress inspection "HttpUrlsUsage"
 malformedProxyAddress=\
 Malformed proxy URI (expecting `http://<host>[:<port>]`): `{0}`.
+
+cannotAnalyzeBecauseSyntaxError=\
+Found a syntax error when parsing module `{0}`.