use ESP-IDF's SPIFFS implementation

[boneskull]

Using this and v0.2.1 of mkspiffs I was able to actually get SPIFFS working:

I'm unsure how to test this more thoroughly. Also: I haven't sent this much C in a PR to any project before; please be gentle. 😇

---

• removes components/spiffs/
• adds custom partition table
• update block size as per ESP-IDF docs
• updates sdkconfig with partition table and whatever else make menuconfig now stuffs in there
• remove unused function esp32_duktape_spiffs_write

[boneskull]

I think maybe sdkconfig shouldn't actually be under VCS...? I think it can pull defaults from somewhere? We need to point it at the partition CSV afaik.

[nkolban]

It has always been my belief that Pull Requests should be honored as quickly as possible. Too many projects suffer from pull requests just sitting in the queue without attention. My philosophy is to merge a pull request ASAP and if there is something wrong with it, we can always back it out later.

[dashxdr]

I can almost get this working. I had to add a partitions.csv line
SPIFFS,data,SPIFFS,0x180000,0x80000,
The directory listing works and file stat + such, but actually reading from a file fails
I've tried the mentioned mkspiffs 0.2.1 and the one included in duktape-esp32/bin, both fail.
I've turned on SPIFFS_DBG logging, the 2 different mkspiffs generate different output
0.2.1 version:
D (27595) SPIFFS: read: offset:0 rd:128 data spix:0000 is data_pix:ffff addr:00ffff05
stock mkspiffs binary from duktape-esp32/bin
D (1123255) SPIFFS: read: offset:0 rd:128 data spix:0000 is data_pix:0000 addr:00000005