Unite p2sAddress and p2shAddress routes (#2213)

[beejaygee]

Closes #2213

Summary

ScriptApiRoute.p2sAddressR and p2shAddressR were nearly identical, differing only in whether the compiled ErgoTree was wrapped with Pay2SAddress.apply or Pay2SHAddress.apply, per the repo's own // todo: unite p2sAddress and p2shAddress comment referencing this issue.

Extracted the shared logic into compiledAddressR(wrapAddress: ErgoTree => ErgoAddress), and both routes now delegate to it:

private def p2sAddressR: Route = path("p2sAddress") { compiledAddressR(Pay2SAddress.apply) }
private def p2shAddressR: Route = path("p2shAddress") { compiledAddressR(Pay2SHAddress.apply) }

No behavior change: same request handling, validation, and response shape for both routes.

Testing

sbt "testOnly org.ergoplatform.http.routes.ScriptApiRouteSpec" — 10/10 passed, run in an isolated Docker sandbox against upstream master (4a7dba0), including the two directly relevant cases:

[info] ScriptApiRouteSpec:
[info] - should execute script with context
[info] - should generate valid P2SAddress form source
[info] - should generate valid P2SHAddress form source
[info] - should get through address <-> ergoTree round-trip
[info] - should address <-> bytes roundtrip via addressToBytes
[info] - should generate addresses with different tree versions
[info] - should handle tree version 2 for P2SH address
[info] - should generate consistent addresses for same script and version
[info] - should generate different addresses for different tree versions
[info] - should handle P2SH with tree version 1 (should still use version 0)
[info] Tests: succeeded 10, failed 0, canceled 0, ignored 0, pending 0

Note on prior attempt

An earlier PR for this issue (#2250) received a maintainer approval (@kushti) but was closed unmerged without comment, and no PR has been open against it since. Reserved via ErgoDevs/Ergo-Bounties before opening this.