fix enforce-pact-version decimal parser

[emilypi]

enforce-pact-version was actually using lexicographic comparison due to the fact that the digit-parser is a stringy parser:

The problem:

П> AP.parseOnly (AP.many1 AP.digit) "10"
Right "10"

Which leads to the following case for the first time in Pact's history, now that it has a double-digit version part:

pact> (enforce-pact-version "4.3.1" "4.10.1")
<interactive>:0:0:Error: Invalid pact version 4.10, minimum allowed: 4.3.1
 at <interactive>:0:0: (enforce-pact-version "4.3.1" "4.10.1")

🎉

This PR uses integer parsing on the version segments:

pact> (enforce-pact-version "4.3.1" "4.10.1")
true

PR checklist:

• Test coverage for the proposed changes
• PR description contains example output from repl interaction or a snippet from unit test output
  * [ ] Documentation has been updated if new natives or FV properties have been added. To generate new documentation, issue cabal run tests. If they pass locally, docs are generated.
  * [ ] Any changes that could be relevant to users have been recorded in the changelog
  * [ ] In case of changes to the Pact trace output (pact -t), make sure pact-lsp is in sync.

Additionally, please justify why you should or should not do the following:

• Confirm replay/back compat
• Benchmark regressions
• (For Kadena engineers) Run integration-tests against a Chainweb built with this version of Pact

[0xd34df00d]

Should this change be under a flag?

It probably shouldn't, since there is no difference in behavior for the already running nodes, and the version where it'd make a difference isn't deployed yet, so it's OK.

[rsoeldner]

This PR closed #1334

[emilypi]

Fixes #1327