[blockly] Persistence: Enhance existing blocks & add blocks to cover …

…all available actions (#2596)

Closes #2595.

This PR further extends the Blockly capabilities to include more of the persistence extensions.

Specifically enhanced the `oh_get_persistvalue` block:
- Add all `Between` methods of already existing methods
- Add `countSince`, `countUntil` and `countBetween`
- Add `countStateChangesSince`, `countStateChangesUntil` and `countStateChangesBetween`
- Add `getAllStatesSince`, `getAllStatesUntil`, `getAllStatesBetween` returning an Array of timestamp and state pairs
- Add a parameter for return type if relevant (`String`, `Number`, `Quantity`, `Timestamp`).

Added methods to the `oh_get_persistence_lastupdate` block:
- `lastChange`, `nextChange`

Created a new block `oh_delete_persistedvalues` to delete persisted values:
- `deleteAllStatesSince`, `deleteAllStatesUntil`, `deleteAllStatesBetween`

Created a new block `oh_persist` to persist values:
- `currentState`: persists a state at the current time
- `stateAt`: persists a state to a given time
- `stateList`: persists a TimeSeries

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Signed-off-by: Mark Herwege <mark.herwege@telenet.be>