feat: provider timeouts

[adamewozniak]

Description

Necessary feature for non-websocket providers that take long enough to retrieve prices that it disrupts the voting mechanism, causing periodic loss of exchange rates & missed vote periods for validators.

closes: #674

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added appropriate labels to the PR
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[adamewozniak]

Need to ignore this for the mock provider, which can take up to 1.8s apparently - no clean way to do this inline, so going to have to make this a part of the config

[toteki]

Making it part of config might help in the long run anyway, so that works