Add new NimBLEUUID constructor, solves #17

[Jeroen88]

Adding to NimBLEUUID.h:

NimBLEUUID(uint32_t first, uint16_t second, uint16_t third, uint64_t fourth);

and to NimBLEUUID.cpp:

NimBLEUUID::NimBLEUUID(uint32_t first, uint16_t second, uint16_t third, uint64_t fourth) {
    m_uuid.u.type        = BLE_UUID_TYPE_128;
    memcpy(m_uuid.u128.value + 12, &first,  4);
    memcpy(m_uuid.u128.value + 10, &second, 2);
    memcpy(m_uuid.u128.value + 8,  &third,  2);
    memcpy(m_uuid.u128.value,      &fourth, 8);
    m_valueSet = true;
}

This does not save any library memory, but is does save sketch memory. In stead of

BLEUUID("ebe0ccb0-7a0a-4b0c-8a1a-6ff2997da3a6")

you can do

BLEUUID(0xebe0ccb0, 0x7a0a, 0x4b0c, 0x8a1a6ff2997da3a6)

thus trading 37 bytes of the string literal for 16 bytes uint literals, saving 21 bytes per UUID literal!

[h2zero]

Could we change this to:

 * @brief Create a UUID from the 128bit value using hex parts instead of string, 
 * instead of BLEUUID("ebe0ccb0-7a0a-4b0c-8a1a-6ff2997da3a6"), it becomes 
 * BLEUUID(0xebe0ccb0, 0x7a0a, 0x4b0c, 0x8a1a6ff2997da3a6)

for better presentation?

[Jeroen88]

Sure

[h2zero]

Looks good, just a couple minor things.

Could you change the title to: Add new NimBLEUUID constructor, solves #17

[h2zero]

Thanks!