UI doesn't report reserved resources correctly (cpu and memory)

Hi folks,

Related to our mistake in #8689, after fixing the memory reserved to be 50% of the node, the client in the UI will still report the full memory and CPU.

The VM has 985 MiB of memory, using the following `reserved` params:

```json
"reserved": {
"memory": 493,
"cpu": 259
},
```

Nomad UI:


Trying to schedule a job with 512 MiB of memory fails **as expected** (so we got the reserved logic right 🤟 ):

```
==> Evaluation "f4037bba" finished with status "complete" but failed to place all allocations:
Task Group "httpbin" (failed to place 1 allocation):
* Resources exhausted on 1 nodes
* Dimension "memory" exhausted on 1 nodes
Evaluation "19e8bfe9" waiting for additional capacity to place remainder
```

@jrasell I'm fairly confident this is misleading.

Let us know, cheers!

Start by reproducing the Nomad UI report with the 985 MiB node and the reserved CPU and memory values from the issue, then trace the UI's resource display. Compare the displayed totals with the scheduling behavior described in the issue. Done means the UI reports resource capacity consistently with the reserved values while the existing scheduling behavior remains unchanged.

Written by the indexing model from the issue text.