Clarifying SVN vs. Version.

This commit updates `framework_svn` and `api_svn` to be named `framework_version` and `api_version`,
respectively. The original names were to represent a *semantic* version number, which was confusing
in this context where SVN more commonly means *security* version number. Accordingly, the
`minimum_svn` and `svn` fields for fragments will remain with the existing naming scheme but their
support has been expanded to allow these strings to also be monotonically increasing integers, to
be more in line with expectations around SVNs.

To provide a smooth transition, support for semantically versioned fragments and the `*_svn` naming
scheme remain in the framework, but in a deprecated state. As part of this, the policy engline will
provide a new error when the type of SVN is different between the SVN of the fragment and the
`minimum_svn` property of a fragment policy object: `fragment svn and the specified minimum are different types`.

Signed-off-by: Matthew A Johnson <matjoh@microsoft.com>

internal/cosesign1/infra.rego

@@ -1,6 +1,7 @@
 package infra
 
-svn := "1.0.0"
+svn := "1"
+framework_version := "0.1.0"
 
 containers := [
  {

internal/tools/policyenginesimulator/README.md

@@ -138,7 +138,7 @@ for more detail.
 ``` rego
 package policy
 
-api_svn := "0.7.0"
+api_version := "0.7.0"
 
 import future.keywords.every
 import future.keywords.in
@@ -187,7 +187,7 @@ reason := {"errors": data.framework.errors}
 ``` rego
 package policy
 
-api_svn := "0.7.0"
+api_version := "0.7.0"
 
 overlays := {
  "pause": {

internal/tools/policyenginesimulator/samples/simple_custom/policy.rego

@@ -1,6 +1,6 @@
 package policy
 
-api_svn := "0.7.0"
+api_version := "0.7.0"
 
 overlays := {
  "pause": {