Python: fix parsing of types in mcp server

[eavanvalkenburg]

Motivation and Context

The parsing of tool call output was not working correctly, this fixes that.
Solves #12850

Description

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[moonbox3]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
connectors
mcp.py	423	207	51%	75, 87, 95–102, 108–109, 114, 126–133, 141–145, 147–148, 150, 157–159, 244–250, 285–287, 292–294, 308–309, 312–313, 321–323, 335–336, 340–341, 343, 345, 347–353, 357–359, 361–371, 375–376, 380–381, 385, 387, 391–392, 396, 410, 425–433, 439–440, 442–443, 446–447, 453–454, 469–470, 473–474, 477–482, 486–487, 490–491, 494–500, 574, 576, 643, 645, 647, 649, 718, 720, 722, 724, 726, 784, 827–832, 834–837, 842, 895, 897, 900, 913, 933–935, 942–947, 950–953, 956–958, 962–966, 969–970, 979–980, 982–984, 998–999, 1001–1002, 1004–1006, 1009, 1016–1019, 1027, 1032–1037, 1042, 1044, 1047–1050
TOTAL	26790	4587	82%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3680	22 💤	0 ❌	0 🔥	2m 0s ⏱️