Consistent resource management across actions and resource types

### Description of the feature request:

There are several way of defining and allocating resources for bazel:
- `--local_cpu_resources` and `--local_ram_resources` can be used to define the amount of cpu and ram available for bazel to consume. They both accept decimal values (float)
- `--local_extra_resources` can be used to model arbitrary abstract resources, also as floats
- The `cpu:` tag (or execution info) can be used to request more cpus for an action (defaults to 1)
- Only works for tests
- Only allows integer values, but it is modelled internally as a double
- The `resources::` can be used to request any amount of an arbitrary resource
- Only applied to tests
- Accepts float values
- As far as I understand, there is no way of requesting more memory (ram), even thou it is modelled internally as number of MB (as a double value)

I would like have fine-grained controll on all the resources types and all the actions, with an unified api, which stores all the values as doubles, something like:
- [x] `resources::` allows allocating any resource, including cpu and memory
- [x] `--local_resources==` can be used to specify the amount of any resource available for bazel to use. This would include `cpu` and `memory`
- [x] `--default_test_resources==,,,` allows setting the default allocation for test based on the test size.
- [ ] `--default_resources==` can be used to change the default allocation for all actions
- [ ] `resources::` can be applied to any action (not test only)

_No response_

Start by reviewing Bazel's existing resource flags, test-size defaults, and resource tags to understand how allocations differ between tests and other actions. The requested work is complete when default allocations can be configured for all actions and resource requests apply beyond tests, with coverage for CPU, memory, and arbitrary resources.

Written by the indexing model from the issue text.